Galactic Astronomy

Progress in many areas of astronomy requires large-area surveys and observations of extended objects. This includes the cosmic microwave background, nearby galaxies, the Milky Way, and regions of star-forming regions within our galaxy. The ability to carry out such studies is critically dependent on the development of affordable high-sensitivity focal plane arrays, for both spectral line and continuum observations. We discuss a program for the next decade to develop such technology for ground-based and spacebased millimeter and submillimeter astronomy. Appropriate technologies exist, but significant effort is required to make the transition from simply replicating individual pixels to approaching focal plane array design in an integrated fashion from feeds to spectrometers for spectral analysis. This advance is essential to realize the full potential of major new ground-based, suborbital, and future space facilities, and is relevant to the RMS and EOS panels. The recommended budget ...

A new seven-beam 6-7 GHz receiver has been built to survey the Galaxy and the Magellanic Clouds for newly forming high-mass stars that are pinpointed by strong methanol maser emission at 6668 MHz. The receiver was jointly constructed by Jodrell Bank Observatory (JBO) and the Australia Telescope National Facility (ATNF) and allows simultaneous coverage at 6668 and 6035 MHz. It was successfully commissioned at Parkes in 2006 January and is now being used to conduct the Parkes-Jodrell multibeam maser survey of the Milky Way. This will be the first systematic survey of the entire Galactic plane for masers of not only 6668-MHz methanol, but also 6035-MHz excited-state hydroxyl. The survey is two orders of magnitude faster than most previous systematic surveys and has an rms noise level of ∼0.17 Jy. This paper describes the observational strategy, techniques and reduction procedures of the Galactic and Magellanic Cloud surveys, together with deeper, pointed, follow-up observations and complementary observations with other instruments. It also includes an estimate of the survey detection efficiency. The 111 d of observations with the Parkes telescope have so far yielded >800 methanol sources, of which ∼350 are new discoveries. The whole project will provide the first comprehensive Galaxy-wide catalogue of 6668-MHz and 6035-MHz masers.

We propose Dual Gravity (DG), an extension of Newtonian and relativistic gravitation incorporating three modulation layers: rotational correction, local energy-density gradients, and galactic-scale quantum harmonic coupling. Unlike uniform energy-density terms excluded by existing experiments (GPS, GRACE, Gravity Probe B), we explicitly define a normalized local energy-density gradient () to capture spatiotemporal fluctuations in thermal, electromagnetic, and bioenergetic fields. The DG model is formulated as: g_{DG} = g_N \cdot \Big(1-\chi(\phi) \Big) \cdot \Big(1 + \beta E_d + \gamma Q_f \Big), where is Newtonian gravity, the rotational share (centrifugal + frame-dragging), the normalized energy-density gradient, and the galactic modulation factor. Coupling coefficients () are tightly bounded by existing data. We present three falsifiable predictions: 1. Atomic/quantum clock drift in controlled energy-density gradient fields, 2. Gravimetric anomalies under superconducting excitation, 3. Null-phase modulations at L2 orbital positions. This framework provides a testable, life-centered extension of gravitation that connects local environments to cosmic-scale dynamics.
https://doi.org/10.5281/zenodo.17228247

Orbiting Astronomical Satellite for Investigating Stellar Systems (OASIS) is a space-based, MIDEX-class mission concept that employs a 17-meter diameter inflatable aperture with cryogenic heterodyne receivers, enabling high sensitivity and high spectral resolution (resolving power >10 6 ) observations at terahertz frequencies. OASIS science is targeting submillimeter and far-infrared transitions of H2O and its isotopologues, as well as deuterated molecular hydrogen (HD) and other molecular species from 660 to 80 µm, which are inaccessible to ground-based telescopes due to the opacity of Earth's atmosphere. OASIS will have >20x the collecting area and ~5x the angular resolution of Herschel, and it complements the shorter wavelength capabilities of the James Webb Space Telescope. With its large collecting area and suite of terahertz heterodyne receivers, OASIS will have the sensitivity to follow the water trail from galaxies to oceans, as well as directly measure gas mass in a wide variety of astrophysical objects from observations of the ground-state HD line. OASIS will operate in a Sun-Earth L1 halo orbit that enables observations of large numbers of galaxies, protoplanetary systems, and solar system objects during the course of its 1-year baseline mission. OASIS embraces an overarching science

This paper proposes Dual Gravity, a two-layer model of gravitation that unifies physical, biological, and cosmological perspectives. Unlike Newtonian gravity, defined solely by mass, or Einstein’s general relativity, rooted in space-time curvature, Dual Gravity introduces a dynamic interaction between three elements: (1) centrifugal force generated by planetary rotation, (2) planetary energy density, including biological/biophysical energy, and (3) resonance with a Galactic Quantum Harmonic Field (GQHF).

We propose testable predictions: (a) high-precision gravimetry may reveal subtle deviations in gravitational acceleration correlated with planetary rotation and latitude; (b) quantum resonance experiments could detect frequency harmonics linking biological systems and planetary gravitational fields. Dual Gravity thus extends gravitation beyond mass and curvature into a multidimensional field interaction, offering a framework for integrating physics with life sciences and cosmology. Further mathematical refinement and experimental validation are essential, and collaboration with research teams in gravimetry and quantum resonance is invited.

Note: This is the full manuscript version submitted to Scientific Reports (Springer Nature). Currently under review.

Using data from the Two Micron All-Sky Survey (2MASS), we identify a population of infrared carbon (IR C) stars with J-K S ≥ 2 in the Milky Way. These stars are shown to trace the stellar bar previously identified in IR and optical surveys. The properties of C stars strongly suggest that they are of intermediate age. We conclude that the bar is likely to have formed more recently than 3 Gyr ago, and must be younger than 6 Gyr. Implications and further tests of this conclusion are briefly discussed.

In its three years of operation, the Sloan Digital Sky Survey (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE-1) observed >14,000 stars with enough epochs over a sufficient temporal baseline for the fitting of Keplerian orbits. We present the custom orbit-fitting pipeline used to create this catalog, which includes novel quality metrics that account for the phase and velocity coverage of a fitted Keplerian orbit. With a typical RV precision of ∼ 100 -200 m s -1 , APOGEE can probe systems with small separation companions down to a few Jupiter masses. Here we present initial results from a catalog of 382 of the most compelling stellar and substellar companion candidates detected by APOGEE, which orbit a variety of host stars in diverse Galactic environments. Of these, 376 have no previously known small separation companion. The distribution of companion candidates in this catalog shows evidence for an extremely truncated brown dwarf (BD) desert with a paucity of BD companions only for systems with a < 0.1 -0.2 AU, with no indication of a desert at larger orbital separation. We propose a few potential explanations of this result, some which invoke this catalog's many small separation companion candidates found orbiting evolved stars. Furthermore, 16 BD and planet candidates have been identified around metal-poor ([Fe/H] < -0.5) stars in this catalog, which may challenge the core accretion model for companions > 10M Jup . Finally, we find all types of companions are ubiquitous throughout the Galactic disk with candidate planetary-mass and BD companions to distances of ∼ 6 and ∼ 16 kpc, respectively.

We are standing at the crossroads of powerful new facilities emerging in the next decade on the ground and in space like ELT, SKA, JWST, and Athena. Turning the narrative of the star formation potential of galaxies into a quantitative theory will provide answers to many outstanding questions in astrophysics, from the formation of planets to the evolution of galaxies and the origin of heavy elements. To achieve this goal, there is an urgent need for a dedicated space-borne, far-infrared spectroscopic facility capable of delivering, for the first time, large scale, high spectral resolution (velocity resolved) multiwavelength studies of the chemistry and dynamics of the ISM of our own Milky Way and nearby galaxies. The Far Infrared Spectroscopic Surveyor (FIRSS) fulfills these requirements and by exploiting the legacy of recent photometric surveys it seizes the opportunity to shed light on the fundamental building processes of our Universe.

The current results of our ongoing Galactic Center (GC) observations with optical long baseline interferometry (OLB-IF) are presented. We achieved first IR-IF fringes in both available IR science regimes of the VLTI (MIDI: 10 µm) and (AMBER: 2 µm), demonstrating the new capabilities provided by large aperture telescope arrays to the Galactic center research. We show that the highest angular resolution only available through interferometric techniques is necessary to observe the GC ISM production in the making and distinguish individual sources from its dusty surroundings. An overview over the currently available IF-technology is given, biased towards the GC science case. The feasibility of phase-referencing to the supergiant GCIRS 7, located only 5 away from SgrA*, to increase the sensitivity and spectral resolution of the observations, is discussed, and supported by the first real data. The presentation will conclude with an outlook to the near future about how the upcoming astrometric and off-axis phase-referencing capabilities of the Keck and VLT Interferometers, nicknamed ASTRA and PRIMA, will greatly extend the currently existing capabilities to observe astrophysical phenomena in the Galactic center at the borderline to General relativity in a yet uninvestigated regime.

The interstellar comet 3I/ATLAS, traveling at 130,000 mph through our solar system, represents far more than a cosmic curiosity-it's a living archive of 7.6 billion years of universal assembly processes. Through Assembly Time analysis and entrainment theory, we demonstrate how this ancient traveler carries within its structure the accumulated history of gravitational encounters, stellar interactions, and cosmic evolutionary processes that span nearly twice the age of our solar system. This case study reveals how objects don't simply "exist" with fixed properties, but rather represent dynamic assembly configurations continuously modified by their journey through the universe's entrainment networks.

Ground-based observations at terahertz (THz) frequencies are a newly explorable area of astronomy in the coming decades. We discuss science cases for a first-generation 10-m class THz telescope, focusing on the Greenland Telescope as an example of such a facility. We propose science cases and provide quantitative estimates for each case. The largest advantage of ground-based THz telescopes is their higher angular resolution (∼ 4 for a 10-m dish), as compared to space or airborne THz telescopes. Thus, highresolution mapping is an important scientific argument. In particular, we can isolate zones of interest for Galactic and extragalactic star-forming regions. The THz windows are suitable for observations of high-excitation CO lines and [N II] 205-μm lines, which are scientifically relevant tracers of star formation and stellar feedback. Those lines are the brightest lines in the THz windows, so they are suitable for the initiation of groundbased THz observations. THz polarization of star-forming regions can also be explored since it traces the dust population contributing to the THz spectral peak. For survey-type observations, we focus on "sub-THz" extragalactic surveys, the uniqueness of which is

This work constructs a unified theoretical framework for understanding galaxies as recursive causal systems. By integrating stellar formation, dark matter scaffolding, entropic dynamics, and symbolic recursion, we argue that galaxies are not merely gravitational collections of matter but complex feedback organisms that encode memory, resonance, and systemic identity. The framework introduces new metrics such as the Geometric Stability Index (GSI), Phase Coherence (Φ), and the Rebirth Potential Index (RPI) to model systemic persistence and collapse. We propose that galactic death results not only from material exhaustion but from recursive misalignment and symbolic incoherence. This model situates galaxies as critical filters in universal evolution and as platforms for symbolic recursion and civilizational persistence.

One of the James Webb Space Telescope's (JWST) primary science goals is to characterize the epoch of galaxy formation in the universe and observe the first galaxies and clusters of galaxies. This goal requires multi-band imaging and spectroscopic data in the near infrared portion of the spectrum for large numbers of very faint galaxies. Because such objects are sparse on the sky at the JWST resolution, a multi-object spectrograph is necessary to efficiently carry out the required observations. We have developed a fully programmable array of microshutters that will be used as the field selector for the multi-object Near Infrared Spectrograph (NIRSpec) on JWST. This device allows apertures to be opened at the locations of selected galaxies in the field of view while blocking other unwanted light from the sky background and bright sources. In practice, greater than 100 objects within the field of view can be observed simultaneously. This field selection capability greatly improves the sensitivity and efficiency of NIRSpec. In this paper, we describe the microshutter arrays, their development, characteristics, fabrication, testing, and progress toward delivery of a flight-qualified field selection subsystem to the NIRSpec instrument team.

The James Webb Space Telescope (JWST) relies on several innovations to complete its five year mission. One vital technology is microshutters, the programmable field selectors that enable the Near Infrared Spectrometer (NIRSpec) to perform multi-object spectroscopy. Mission success depends on acquiring spectra from large numbers of galaxies by positioning shutter slits over faint targets. Precise selection of faint targets requires field selectors that are both high in contrast and stable in position. We have developed test facilities to evaluate microshutter contrast and alignment stability at their 35K operating temperature. These facilities used a novel application of image registration algorithms to obtain non-contact, sub-micron measurements in cryogenic conditions. The cryogenic motion of the shutters was successfully characterized. Optical results also demonstrated that shutter contrast far exceeds the NIRSpec requirements. Our test program has concluded with the delivery of a flight-qualified field selection subsystem to the NIRSpec bench.

A recent investigation of radio sources in the northern hemisphere was made by Kellermann (1966). He attempted to explain some of the characteristics of the sources that were observed to have c~ed spectra. In order to make a similar investigation possible for sources in the southern hemisphere, more observations especially at low frequencies are needed. Recently surveys have been published at 153 MHz (Hamilton and Haynes 1967) and between 40 and 120 MHz (Haynes and Hamilton 1968). Contuluing these observations, we report here on measurements of 11 radio sources made at the Australian National Radio Astronomy Observatory, Parkes, N.S.W., in January 1968.

The Infra-Red Imaging Spectrograph (IRIS) is one of the three first light instruments for the Thirty Meter Telescope (TMT) and is the only one to directly sample the diffraction limit. The instrument consists of a parallel imager and offaxis Integral Field Spectrograph (IFS) for optimum use of the near infrared (0.84um-2.4um) Adaptive Optics corrected focal surface. We present an overview of the IRIS spectrograph that is designed to probe a range of scientific targets from the dynamics and morphology of high-z galaxies to studying the atmospheres and surfaces of solar system objects, the latter requiring a narrow field and high Strehl performance. The IRIS spectrograph is a hybrid system consisting of two state of the art IFS technologies providing four plate scales (4mas, 9mas, 25mas, 50mas spaxel sizes). We present the design of the unique hybrid system that combines the power of a lenslet spectrograph and image slicer spectrograph in a configuration where major hardware is shared. The result is a powerful yet economical solution to what would otherwise require two separate 30m-class instruments.

Measurements of the cosmic ray p/p ratio are compared to predictions from an inhomogeneous leaky box model of Galactic secondary p production combined with an updated heliospheric model that modulates the predicted fluxes measured at the Earth. The heliospheric corrections are crucial for understanding the low-energy part of the spectrum. The p production-propagation-modulation model agrees with observations. Adding a finite p lifetime to the model, we obtain the limit τ p > 1.7 Myr (90% C.L.). Restrictions on heliospheric properties and the cutoff of low-energy interstellar cosmic rays are discussed.

LINC-NIRVANA (LN) is a Fizeau interferometer that will provide for the first time coherent images in the near-IR combining the beams from the two Large Binocular Telescope (LBT)arms, by adopting a Multi-Coniugate Adaptive Optics system (MCAO) that allows for atmospheric turbulence compensation. We applied a software for the simulation and the reconstruction of LN images (AIRY-LN, see Desiderá et al. 1 this Conference) in two specific scientific cases: a relatively distant galaxy at redshift about 1 and a collimated jet from a Young Stellar Object (YSO). These two cases have been chosen to test the capability of LN in the observations of faint and small (1-2 arcsec) extragalactic objects and objects with diffuse emission and high dynamical range, respectively. A total of six images at different hour angles have been obtained for both cases. Using these simulated images, we obtained the final reconstructed images using the software package AIRY-LN. These images have been analyzed with the standard data reduction software (IRAF and IDL). Our analysis show that the reconstruction algorithm is fundamental to obtain a good reproduction of the original flux and morphology while the optimal number of iterations strongly depends on the scientific goal.

We present a preliminary design study for an adaptive optics visual echelle spectrograph and imager/coronograph for use as parallel instrument of the Nasmyth Adaptive Optics System (NAOS) on unit UT3 (Melipal) of the VLT. The spectrograph is intended for intermediate (R'-'16OOO) resolution spectroscopy of faint (sky and/or detector limited) sources. It could be used for observations of late-type dwarfs in distant Galactic clusters and in galaxies of the local group as well as for spectroscopy of extragalactic objects like quasars and Lyman break galaxies down to a limiting magnitude of V = 22.5. The implementation of an imaging and coronograph mode increases the versatility of the instrument and its scientific objectives. The instrument takes advantage of Adaptive Optics at visible wavelengths (V, R and I bands) both for imaging and spectroscopy. With NAOS at the VLT, the light concentration in these bands will be above ' 60% of the flux in a 0.3 arcsec aperture for typical Paranal conditions. Simulations show that a gain of more than one magnitude with respect to comparable non-adaptive optical spectrographs will be possible for sky-and/or detec1or limited observations. In addition, the smaller diffraction limit in the optical than in the JR will allow a significant gain in imaging and coronography as well. Finally, the instrument will allow gathering unprecedented experience on the performances of AO at visible wavelengths, which wifi be fundamental for further development of AO systems, in particular for very large telescopes.

We present the discovery of **kinematic star towers** in Gaia DR3 (4-20 kpc), featuring three anomalous signatures that collectively challenge standard galactic dynamics:

1. **Vertical Lamination**:
  - Stellar structures quantized in ∆z ≈ 0.1 kpc layers
  - Correlated with velocity dispersion drops to σv = 30 km/s at 7-8 kpc

2. **Phase-Coherent Waves**:
  - Unmodeled λ = 3.2 kpc sinusoids in radial velocities (p < 0.001 vs Gaussian)
  - Persistent across Solar/Galactic reference frames

3. **Metallicity Dip** (New in v2):
  - [Fe/H] depression of 0.25 ± 0.03 dex at 7-8 kpc
  - Stellar population ~2-3 Gyr older than adjacent regions

These patterns match predictions of **PBH-evaporation scars** ([1], Eq.14), exhibiting:
- Topological memory in stellar orbits
- Chemical filtering of metal-poor stars
- Resonant kinematic structures

The combined evidence rejects ΛCDM's collisionless halo paradigm at >5σ confidence. All Gaia DR3 queries [2], analysis codes, and metallicity maps are publicly available.

**Key Advance in v2**:
- Metallicity analysis confirms the **topological nature** of the 7-8 kpc anomaly
- Quantitative link between [Fe/H] dip and PBH mass (10³ M⊙)

The Reflection Grating Spectrometer of the Constellation-X mission has two strong candidate configurations. The first configuration, the in-plane grating (IPG), is a set of reflection gratings similar to those flown on XMM-Newton and has grooves perpendicular to the direction of incident light. In the second configuration, the off-plane grating (OPG), the grooves are closer to being parallel to the incident light, and diffract along a cone. It has advantages of higher packing density, and higher reflectivity. Confinement of these gratings to sub-apertures of the optic allow high spectral resolution. We have developed a raytrace model and analysis technique for the off-plane grating configuration. Initial estimates indicate that first order resolving powers in excess of 1000 (defined with half-energy width) are achievable for sufficiently long wavelengths (λ 12 Å), provided separate accommodation is made for gratings in the subaperture region farther from the zeroth order location.

For decades, and even now, our expectation of alien contact has only existed in terms of direct physical contact. It does not take into account, however, an obvious phenomenon of the Universethe enormous distances between cosmological objects. We propose the model, which is based on an interaction between civilizations of different planets, where information exchange and direct contact are significantly separated in time. Any civilization, including earth's, will be granted a safe Extraterrestrial Contact Window, the size of which depends on the distance between civilizations and the achieved speed of spaceships. An important conclusion is that good morality in inter civilizational interaction has a greater chance of prevailing than the so-called evil civilization, the spread of which is impeded by a barrier of the size of a sphere of several thousand light years. Furthermore, this paper places great importance on finding a technology based on quantum entanglement, as this could potentially give us the ability to exchange information instantaneously, i.e., with infinite speed.

We describe the Galaxy Evolution Explorer (GALEX) satellite that was launched in April 2003 specifically to accomplish far ultraviolet (FUV) and near ultraviolet (NUV) imaging and spectroscopic sky-surveys. GALEX is currently providing new and significant information on how galaxies form and evolve over a period that encompasses 80% of the history of the Universe. This is being accomplished by the precise measurement of the UV brightness of galaxies which is a direct measurement of their rate of star formation. We briefly describe the design of the GALEX mission followed by an overview of the instrumentation that comprises the science payload. We then focus on a description of the development of the UV sealed tube micro-channel plate detectors and provide data that describe their on-orbit performance. Finally, we provide a short overview of some of the science highlights obtained with GALEX.

We use 3653 (2661 RRab, 992 RRc) RR Lyrae stars (RRLs) with 7D (3D position, 3D velocity, and metallicity) information selected from Sloan Digital Sky Survey, Large Sky Area Multi-Object Fiber Spectroscopic Telescope, and Gaia EDR3, and divide the sample into two Oosterhoff groups (Oo I and Oo II) according to their amplitude–period behaviour in the Bailey diagram. We present a comparative study of these two groups based on chemistry, kinematics, and dynamics. We find that Oo I RRLs are relatively more metal-rich, with predominately radially dominated orbits and large eccentricities, while Oo II RRLs are relatively more metal-poor, and have mildly radially dominated orbits. The Oosterhoff dichotomy of the Milky Way’s halo is more apparent for the inner-halo region than for the outer-halo region. Additionally, we also search for this phenomenon in the haloes of the two largest satellite galaxies, the Large and Small Magellanic clouds, and compare over different bins in metallicity. W...

The High Efficiency and Resolution Multi Element Spectrograph, HERMES is an facility-class optical spectrograph for the Anglo-Australian Telescope. It is designed primarily for Galactic Archaeology , the first major attempt to create a detailed understanding of galaxy formation and evolution by studying the history of our own galaxy, the Milky Way. The goal of the GALAH survey is to reconstruct the mass assembly history of the of the Milky Way, through a detailed chemical abundance study of one million stars. The spectrograph is based at the AAT and is fed by the existing 2dF robotic fiber positioning system. The spectrograph uses VPH gratings to achieve a spectral resolving power of 28,000 in standard mode and also provides a high-resolution mode ranging between 40,000 to 50,000 using a slit mask. The GALAH survey requires a SNR greater than 100 for a star brightness of V=14 in an exposure time of one hour. The total spectral coverage of the four channels is about 100nm between 370 and 1000nm for up to 392 simultaneous targets within the 2 degree field of view. HERMES has been commissioned over 3 runs, during bright time in October, November and December 2013, in parallel with the beginning of the GALAH Pilot survey, which started in November 2013. In this paper we present the first-light results from the commissioning run and the beginning of the GALAH Survey, including performance results such as throughput and resolution, as well as instrument reliability.

Radio emission has been detected in a broad variety of stellar objects from all stages of stellar evolution. However, most of our knowledge originates from targeted observations of small samples, which are strongly biased to sources which are peculiar at other wavelengths. In order to tackle this problem we have conducted a deep 1.4 GHz survey by using the Australian Telescope Compact Array, with a net bandwidth of 1.7 GHz (1.4-3.1 GHz) , following the same observing setup as that used for the Australia Telescope Large Area Survey project, this time choosing a region more appropriate for stellar work. In this paper, the Stellar Continuum Originating from Radio Physics In Ourgalaxy (SCORPIO) project is presented as well as results from the pilot experiment. The achieved rms is 30 µJy and the angular resolution ∼10 arcsec. 614 point-like sources have been extracted just from the pilot field. Only 34 of them are classified in SIMBAD or the NASA/IPAC Extragalactic Database. About 80 per cent of the extracted sources are reported in one of the inspected catalogues and 50 per cent of them appears to belong to a reddened stellar/Galactic population. However, the evaluation of extragalactic contaminants is very difficult without further investigations. Interesting results have been obtained for extended radio sources that fall in the SCORPIO field. Many roundishlike structures (indicated as bubbles in the following) have been found, some of which are classified at other wavelengths. However, for all of these sources, our project has provided us with images of unprecedented sensitivity and angular resolution.

Стаття присвячена дослідженню життя і творчості вітчизняного астронома М.С. Саврона, фахівця у галузі галактичної та позагалактичної астрономії. Висвітлено етапи наукового шляху талановитого вченого, астронома-спостерігача, який вивчав фізичні характеристики Сонця, успішно фотографував малі планети і астероїди головного поясу (Аквітанію, Весту, Іриду, Флору, Цереру), здійснив серію багаторічних спостережень змінних зір. Саврон одним із перших серед вітчизняних астрономів досліджував змінні зорі, зокрема Нові у сузір’ях Геркулеса, Орла та Ящірки, які, за сучасними даними, є проміжними поляра-ми (DQ Herculis, V603 Aquilae). Астроном вивчав потрійну зоряну систему Дельту Лебедя, спостерігав рідкі зорі О-типу, фотографував відомі кулясті скупчення М13 у сузір’ї Геркулеса та М15 у сузір’ї Пегаса, в якому також міститься багато змінних зір; досліджував довгоперіодичну комету Джонсона (1936). В Харківській астрономічній обсерваторії Саврон виконав ґрунтовну науково-дослідницьку роботу, присвячену проблемі поглинання фотографічних променів в атмосфері Землі. У складі делегації харківських астрономів взяв участь у спостереженнях так званого «Великого радянського затемнення» — повного сонячного затемнення 1936 р. Наведено приклади співпраці астронома з провідними ученими Харківської астрономічної обсерваторії проф. Б.П. Герасимовичем, проф. М.П. Барабашовим, Б.Є. Сємейкіним та П.Г. Пархоменко; показано участь Саврона у розбудові інструментальної бази обсерваторії; проаналізовано його наукові публікації. Розглянуто адміністративно-педагогічну діяльність ученого у закладах вищої освіти: в Харківському державному університеті імені О.М. Горького, Харківському державному педагогічному інституті імені Г.С. Сковороди, зокрема на посадах декана географічного та фізико-математичного факультетів, завідувача кафедри астрономії. Документально підтверджено діяльність проф. М.С. Саврона під час Другої світової війни, зокрема висвітлено його участь в організації Ради наук у Харкові та роботу в Науково-технічній управі під час німецької окупації міста у 1941–1943 рр. / The article focuses on the studying the life and work of the Ukrainian astronomer M.S. Sawron, a specialist in the field of galactic and extragalactic astronomy. This research paper has high-lighted the stages of the scientific path of a talented scientist, an astronomer-observer, who studied the physical conditions of the Sun, successfully photographed the minor planets and asteroids of the main belt (Aquitania, Vesta, Iris, Flora, Ceres), implemented a series of long-term observations of variable stars. Sawron was one of the first Ukrainian astronomers who studied variable stars, in particular, Novae in the constellations Hercules, Aquila and Lacerta, which, according to modern data, are intermediate polar (DQ Herculis, V603 Aquilae). The astronomer studied the Delta Cygni triple-star system, observed rare O-type stars, and photographed the famous globular clusters M13 in the constellations Hercules and M15 in the constellation Pegasus, which also contains many variable stars; investigated the long-period comet Johnson (1936). At the Kharkiv Astronomical Observatory Sawron performed a fundamental research work devoted to the problem of photographic rays’ absorption in the Earth’s atmosphere. As part of the delegation of Kharkiv astronomers, he took part in the observations of the so-called «The Great Soviet Solar Eclipse» — the total Solar Eclipse of 1936.Examples of cooperation of an astronomer with leading scientists of the Kharkiv Astronomical Observatory prof. B.P. Gerasimovich, prof. M.P. Barabashov, B.E. Semeykin and P.G. Parkhomenko; Sawron’s participation in the development of the instrumental base of the observatory were provided.The administrative and pedagogical activity of the scientist in institutions of higher education is considered: at Gorky Kharkiv State University, Skovoroda Kharkiv State Pedagogical Institute, in particular as dean of the geographical and physical-mathematical faculties, head of the department of astronomy.The activity of prof. M.S. Sawron during the Second World War, his participation in the organization of the Council of Sciences in Kharkiv and his work in the Scientific and technical office during the German occupation of the city in 1941—1943 are substantiated by documents.

In this paper, the frequency allocation reserved for radio astronomy in theLband set by the International Telecommunication Union (ITU), which is between 1400 and 1427 MHz, is reviewed. We argue that the nearby frequencies are still very important for radio astronomers on the ground by investigating radio objects (Hisources) around 1300–1500 MHz. TheL-band window is separated into a group of four windows, namely 1400–1427 MHz (window A), 1380–1400 MHz (window B), 1350–1380 MHz (window C), and 1300–1350 MHz (window D). These windows are selected according to their redshifts from a rest frequency for hydrogen spectral line at 1420.4057 MHz. Radio objects up toz≈ 0.1 or frequency down to 1300 MHz are examined. We argue that since window B has important radio objects within the four windows, this window should also be given to radio astronomy. They are galaxies, spiral galaxies, and galaxy clusters. This underlines the significance of window B for radio astronomers on the ground. By inv...

У статті досліджено життя і творчість вітчизняного астронома М. С. Саврона, фахівця в галузі зоряної астрономії. Проаналізовано наукову діяльність вченого, сфокусовану на вивченні Сонця, великих позагалактичних об'єктів, малих планет, фотометричних дослідженнях нових зір та всебічних дослідженнях змінних зір, спостереженнях сонячних і місячних затемнень; регулярних спостереженнях прозорості земної атмосфери та дослідженнях довгоперіодичних комет. Основні віхи наукової біографії М. С. Саврона реконструйовані на тлі процесу становлення і розвитку Харківської астрономічної обсерваторії у 20-30-ті роки ХХ ст. Розглянуто адміністративно-педагогічну діяльність вченого в Харківському державному університеті імені О. М. Горького, Харківському державному педагогічному інституті імені Г. С. Сковороди, інших установах. Висвітлено участь М. С. Саврона в організації Ради наук у Харкові та його роботу в Науково-технічній управі під час німецької окупації міста у 1941-1943 рр. Публікація ґрунтується на документах державних та відомчих архівів. /  The life and work of the ukrainian astronomer M. S. Savron, a specialist in the field of stellar astronomy, are studied. The scientific activities of the scientist, focused on the study of the Sun, large extragalactic objects, minor planets, photometric studies of new stars and comprehensive studies of variable stars, observations of solar and lunar eclipses; regular observations of the transparency of the Earth's atmosphere and studies of long-period comets, are analyzed. The main milestones of M. S. Savron's scientific biography are reconstructed against the background of the process of formation and development of the Kharkiv Astronomical Observatory in the 20-30s of the twentieth century. The administrative and pedagogical activities of the scientist at the Kharkiv State University named after A. M. Gorky, Kharkiv State Pedagogical Institute named after H. S. Skovoroda, and other institutions are considered. The article highlights M. Savron's participation in the organization of the Council of Sciences in Kharkiv and his work in the Scientific and Technical Administration during the German occupation of the city in 1941-1943.

The W. M. Keck Observatory is designing a new adaptive optics system providing precision AO correction in the near infrared, good correction at visible wavelengths, and multiplexed spatially resolved spectroscopy. We discuss science cases for this Next Generation AO (NGAO), and show how the system requirements were derived from these science cases. Key science drivers include asteroid companions, planets around low-mass stars, general relativistic effects around the Galactic Center black hole, nearby active galactic nuclei, and high-redshift galaxies (including galaxies lensed by intervening galaxies or clusters). The multi-object AO-corrected integral field spectrograph will be optimized for high-redshift galaxy science.

We are designing a next-generation adaptive optics-fed integral field spectrograph (IFS) and imaging camera for the W. M. Keck Observatory. This innovative instrument, known as Liger, will be crucial for exploring a wide range of science cases across cosmic time, such as dark matter substructure, distant galaxies, supermassive black holes, nearby star forming regions, the Galactic Center, and Solar System bodies. Liger is designed to be a facility-class instrument that will enable new science by offering enhanced capabilities such as higher spectral resolving power (R∼8000-10000), access to shorter wavelengths (0.84 2.4 μm), and larger fields of view compared to any current and future groundand space-based IFS systems. The Liger instrument uses the latest near-infrared detectors for an imaging camera that operates simultaneously with an innovative IFS that uses both a slicer and lenslet array for spatial sampling. Liger is being planned for the Keck I telescope to take advantage of ...

GIANO is the high resolution near IR spectrograph recently commissioned at the 3.58m Telescopio Nazionale Galileo in La Palma (Spain). GIANO is the first worldwide instrument providing cross-dispersed echelle spectroscopy at a resolution of 50,000 over the 0.95 -2.45 micron spectral range in a single exposure. There are outstanding science cases in the research fields of exo-planets, Galactic stars and stellar populations that could strongly benefit from GIANO observations down to a magnitude limit comparable to that of 2MASS. The instrument includes a fully cryogenic spectrograph and an innovative fiber system transmitting out to the K band. It also represents a formidable laboratory to test performances and prototype solutions for the next generation of high resolution near IR spectrographs at the ELTs. First results from sky tests at the telescope and science verification occurred between July 2012 and October 2013 will be presented.

During its burst of intraday variation (IDV) in June 1996 quasar PKS 0405–385 exhibited rapid changes in the Stokes parameters Q and U that were even faster than the 1 hr timescale changes in I. Auto- and cross-correlation analyses of I,Q, and U at 8.6 GHz show systematic relations between the variations in I,Q, and U. These are well modelled by interstellar scintillation (ISS) of a 14 × 20 μ as source, with about 180 degree rotation of the polarisation angle along its long dimension. This success in explaining the remarkable IDV in polarisation confirms that ISS gives rise to the IDV in this quasar.

David L. Jauncey∗,aHayley E. Bignall,b Lucyna Kedziora-Chudczerc, Jun Yi Koay,b James E. J. Lovell,d Jean-Pierre Macquart,b Roopesh Ojha,e Tapio Pursimo, f Cormac Reynoldsa and Barney Rickettg aCSIRO Astronomy and Space Science & Mount Stromlo Observatory, Australia bICRAR, Curtin University, Bentley, WA 6102, Australia cSchool of Physics & Astrophysics, University of NSW, Sydney, NSW 2052, Australia dSchool of Mathematics & Physics, University of Tasmania, TAS 7001, Australia eNASA Goddard Space Flight Center, Greenbelt, MD 20771, USA f Nordic Optical Telescope, Apartado 474, 38700 Santa Cruz de La Palma, Spain gDepartment of Electrical & Computer Engineering, UCSD, La Jolla, CA 92093, USA E-mail: David.Jauncey@csiro.au, H.Bignall@curtin.edu.au, lkedzior@unsw.edu.au, Kevin.Koay@icrar.org, Jim.Lovell@utas.edu.au, J.Macquart@curtin.edu.au, Roopesh.Ojha@nasa.gov, tpursimo@not.iac.es, C.Reynolds@curtin.edu.au, bjrickett@ucsd.edu

WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a nearly 1000-multiplex fibre positioner, 20 individually deployable ‘mini’ integral field units (IFUs), and a single large IFU. These fibre systems feed a dual-beam spectrograph covering the wavelength range 366−959 nm at R ∼ 5000, or two shorter ranges at R ∼ 20 000. After summarising the design and implementation of WEAVE and its data systems, we present the organisation, science drivers and design of a five- to seven-year programme of eight individual surveys to: (i) study our Galaxy’s origins by completing Gaia’s phase-space information, providing metallicities to its limiting magnitude for ∼3 million stars and detailed abundances for ∼1.5 million brighter field and open-cluster stars; (ii) survey ∼0.4 million Galactic-plane OBA stars, young stellar objects...

OB associations of young stars are the laboratories that keep track of star formation from the birth of a star cloud to its dissolution. Sco-Cen OB association closest to the Sun is also an example of massive star formation. In this study, we research the Sco-Cen OB association region up to G = 17.5 mag in the circular region within 1 radius centred (l, b) = (322◦, +10◦) due to the high quality of the stellar parallax and proper motions of Gaia DR3. We applied the DBSCAN clustering algorithm to the selected region to identify subgroups and new members of the associations. In total, we identified 40 subgroups and 4777 member stars. We provide cluster analysis of subgroups using PARSEC age isochrones to reveal the star formation history of each region.

One of the James Webb Space Telescope's (JWST) primary science goals is to characterize the epoch of galaxy formation in the universe and observe the first galaxies and clusters of galaxies. This goal requires multi-band imaging and spectroscopic data in the near infrared portion of the spectrum for large numbers of very faint galaxies. Because such objects are sparse on the sky at the JWST resolution, a multi-object spectrograph is necessary to efficiently carry out the required observations. We have developed a fully programmable array of microshutters that will be used as the field selector for the multi-object Near Infrared Spectrograph (NIRSpec) on JWST. This device allows apertures to be opened at the locations of selected galaxies in the field of view while blocking other unwanted light from the sky background and bright sources. In practice, greater than 100 objects within the field of view can be observed simultaneously. This field selection capability greatly improves the sensitivity and efficiency of NIRSpec. In this paper, we describe the microshutter arrays, their development, characteristics, fabrication, testing, and progress toward delivery of a flight-qualified field selection subsystem to the NIRSpec instrument team.

The James Webb Space Telescope (JWST) relies on several innovations to complete its five year mission. One vital technology is microshutters, the programmable field selectors that enable the Near Infrared Spectrometer (NIRSpec) to perform multi-object spectroscopy. Mission success depends on acquiring spectra from large numbers of galaxies by positioning shutter slits over faint targets. Precise selection of faint targets requires field selectors that are both high in contrast and stable in position. We have developed test facilities to evaluate microshutter contrast and alignment stability at their 35K operating temperature. These facilities used a novel application of image registration algorithms to obtain non-contact, sub-micron measurements in cryogenic conditions. The cryogenic motion of the shutters was successfully characterized. Optical results also demonstrated that shutter contrast far exceeds the NIRSpec requirements. Our test program has concluded with the delivery of a flight-qualified field selection subsystem to the NIRSpec bench.

We describe the scientific case and design challenges for an innovative large submillimetre telescope (LST). LST is proposed to have a diameter of at least 30m, operate in the wavelength range from 0.2-1mm and will have a wide field-of-view. The submillimetre region allows us to probe objects during formation-i.e. the earliest evolutionary stages of galaxies, stars and planets. Being so close to the peak of the cosmic far-IR/submm background and the emission from proto-stellar cores, the 200µm atmospheric window gives access to unique science. The key advantage of LST over other facilities will be in terms of addressing astronomical questions requiring large fields and good angular resolution: such as surveys of entire giant molecular clouds and fields of dusty galaxies at early epochs. For example, such a telescope would resolve all protoplanetary disks out to 100pc, revolutionising our knowledge of star and planet formation, and detect tens of millions of dusty high-redshift galaxies yielding information on formation and evolution of the early universe. Equipped with a state-of-the-art large format bolometer camera, LST would offer a survey (mapping) speed up to 5,000 times that of ALMA, arcsecond resolution at the shortest wavelengths, point-source sensitivities at least 25 times better than any planned submm facility, and confusion limits 10 times lower than any existing singleaperture telescope. The wide-field-of-view and superb image fidelity available from a single-dish will be perfect for large-scale surveys of the submillimetre sky − an ideal complement to new generation interferometers such as ALMA.

We report the first results of a study of variable point sources identified using multi-color time-series photometry from Sloan Digital Sky Survey (SDSS) Stripe 82, including data from the SDSS-II Supernova Survey, over a span of nearly ten years (1998-2007). We construct a light-curve catalog of 221,842 point sources in the RA 0 to 4 h half of Stripe 82, limited to r = 22.0 mag, that have at least 10 detections in the ugriz bands and color errors < 0.2 mag. These sources are then classified by color and by cross-matching them to existing SDSS catalogs of interesting objects. Inhomogenous ensemble differential photometry techniques are used to greatly improve our sensitivity to variability and reduce contamination by sources that appear variable due to large photometric noise or systematic effects caused by non-uniform photometric conditions throughout the survey. We use robust variable identification methods to extract 6,520 variable candidates from this dataset, resulting in an overall variable fraction of ∼ 2.9% at the level of ∼ 0.05 mag variability. Despite the sparse and uneven time-sampling of the light-curve data, we discover 143 periodic variables in total. Due to period ambiguity caused by relatively poor phase coverage, we identify a smaller final set of 101 periodic variables with well-determined periods and light-curves. Among these are 55 RR Lyrae, 30 eclipsing binary candidates, and 16 high amplitude Delta Scuti variables. In addition to these objects, we also identify a sample of 2,704 variable quasars matched to the SDSS Quasar Catalog (Schneider et al. 2007), which make up a large fraction of our variable candidates. An additional 2,403 quasar candidates are tentatively identified and selected by their non-stellar colors and variability. A sample of 11,328 point sources that appear to be nonvariable given the limits of our variability sensitivity is also briefly discussed. Finally, we describe several interesting objects discovered among our eclipsing

We describe the Galaxy Evolution Explorer (GALEX) satellite that was launched in April 2003 specifically to accomplish far ultraviolet (FUV) and near ultraviolet (NUV) imaging and spectroscopic sky-surveys. GALEX is currently providing new and significant information on how galaxies form and evolve over a period that encompasses 80% of the history of the Universe. This is being accomplished by the precise measurement of the UV brightness of galaxies which is a direct measurement of their rate of star formation. We briefly describe the design of the GALEX mission followed by an overview of the instrumentation that comprises the science payload. We then focus on a description of the development of the UV sealed tube micro-channel plate detectors and provide data that describe their on-orbit performance. Finally, we provide a short overview of some of the science highlights obtained with GALEX.

The continuum spectrum of the planetary nebula Hf 2-2 close to the Balmer discontinuity is modelled in the context of the long-standing problem of the abundance and temperature discrepancy found when analysing optical recombination lines and collisionally excited forbidden lines in nebulae. Models are constructed using single and double Maxwell-Boltzmann distributions as well as κ-distributions for the energies of the free electrons. New results for the necessary continuum and line emission coefficients are presented calculated with κ-distributed energies. The best fit to the observed continuum spectrum is found to be a model comprising two components with dramatically different temperatures and with a Maxwell-Boltzmann distribution of electron energies. On the basis of a χ 2 analysis, this model is strongly favoured over a model with κ-distributed electron energies.

MOONS is a new conceptual design for a Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope (VLT), selected by ESO for a Phase A study. The baseline design consists of ~1000 fibers deployable over a field of view of ~500 square arcmin, the largest patrol field offered by the Nasmyth focus at the VLT. The total wavelength coverage is 0.8µm-1.8µm and two resolution modes: medium resolution and high resolution. In the medium resolution mode (R~4,000-6,000) the entire wavelength range 0.8µm-1.8µm is observed simultaneously, while the high resolution mode covers simultaneously three selected spectral regions: one around the CaII triplet (at R~8,000) to measure radial velocities, and two regions at R~20,000 one in the J-band and one in the H-band, for detailed measurements of chemical abundances. The grasp of the 8.2m Very Large Telescope (VLT) combined with the large multiplex and wavelength coverage of MOONS-extending into the near-IR-will provide the observational power necessary to study galaxy formation and evolution over the entire history of the Universe, from our Milky Way, through the redshift desert and up to the epoch of re-ionization at z>8-9. At the same time, the high spectral resolution mode will allow astronomers to study chemical abundances of stars in our Galaxy, in particular in the highly obscured regions of the Bulge, and provide the necessary follow-up of the Gaia mission. Such characteristics and versatility make MOONS the long-awaited workhorse near-IR MOS for the VLT, which will perfectly complement optical spectroscopy performed by FLAMES and VIMOS.

We summarize 5 years of continuous monitoring of accretion-powered pulsars with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. Our 2070 keV observations have determined or rened the orbital parameters of 13 binaries, discovered ve new transient accreting pulsars, measured the pulsed ux history during outbursts of 12 transients (GRO J1744[28, 4U 0115]634, GRO J1750[27, GS 0834[430, 2S 1417[624, GRO J1948]32, EXO 2030]375, GRO J1008[57, A0535]26, GRO J2058]42, 4U 1145[619, and A1118[616), and also measured the accretion torque history during outbursts of six of those transients whose orbital parameters were also known. We have also continuously measured the pulsed ux and spin frequency for eight persistently accreting pulsars (Her X-1, Cen X-3, Vela X-1, OAO 1657[415, GX 301[2, 4U 1626[67, 4U 1538[52, and GX 1]4). Because of their continuity and uniformity over a long baseline, BATSE observations have provided new insights into the long-term be...

Fully sampled degree-scale maps of the 13 CO 2-1 and CO 4-3 transitions toward three members of the Lupus Molecular Cloud Complex-Lupus I, III, and IV-trace the column density and temperature of the molecular gas. Comparison with IR extinction maps from the c2d project requires most of the gas to have a temperature of 8-10 K. Estimates of the cloud mass from 13 CO emission are roughly consistent with most previous estimates, while the line widths are higher, around 2 km s −1. CO 4-3 emission is found throughout Lupus I, indicating widespread dense gas, and toward Lupus III and IV. Enhanced line widths at the NW end and along the edge of the B 228 ridge in Lupus I, and a coherent velocity gradient across the ridge, are consistent with interaction between the molecular cloud and an expanding H I shell from the Upper-Scorpius subgroup of the Sco-Cen OB Association. Lupus III is dominated by the effects of two HAe/Be stars, and shows no sign of external influence. Slightly warmer gas around the core of Lupus IV and a low line width suggest heating by the Upper-Centaurus-Lupus subgroup of Sco-Cen, without the effects of an H I shell.