A5043777208- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- Scientific Research and Discoveries
- Astrophysics and Cosmic Phenomena
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Relativity and Gravitational Theory
- Adaptive optics and wavefront sensing
- Impact of Light on Environment and Health
- Historical Astronomy and Related Studies
- Astro and Planetary Science
- Advanced Mathematical Theories and Applications
- Dark Matter and Cosmic Phenomena
- History and Theory of Mathematics
- Advanced Mathematical Theories
- Historical Geography and Cartography
- Calibration and Measurement Techniques
- Black Holes and Theoretical Physics
- Geophysics and Gravity Measurements
Special Astrophysical Observatory
2016-2025
University of Maryland, College Park
2017
Russian Academy of Sciences
2000-2015
Leibniz Institute for Neurobiology
2015
Leibniz Institute for Astrophysics Potsdam
1995-2015
Leibniz Association
2013
Université Claude Bernard Lyon 1
2011
Institute of Nuclear Physics of Lyon
2011
Institut National de Physique Nucléaire et de Physique des Particules
2011
Centre National de la Recherche Scientifique
2011
The recently initiated Arecibo Legacy Fast ALFA (ALFALFA) survey aims to map 7000 square degrees of the high galactic latitude sky visible from Arecibo, providing a HI line spectral database covering redshift range between -1600 km/s and 18,000 with 5 resolution. Exploiting Arecibo's large collecting area small beam size, ALFALFA is specifically designed probe faint end mass function in local universe will provide census surveyed flux limits, making it especially useful synergy wide surveys...
We present an all-sky catalog of 451 nearby galaxies, each having individual distance estimate D ≲ 10 Mpc or a radial velocity VLG < 550 km s-1. The contains data on basic optical and H I properties the in particular, their diameters, absolute magnitudes, morphological types, circumnuclear region surface brightnesses, rotational velocities, indicative mass-to-luminosity ratios, as well so-called tidal index, which quantifies galaxy environment. expect completeness to be roughly 70%–80%...
The ACS Nearby Galaxy Survey Treasury (ANGST) is a systematic survey to establish legacy of uniform multi-color photometry resolved stars for volume-limited sample nearby galaxies (D < 4 Mpc).The volume encompasses 69 in diverse environments, including close pairs, small & large groups, filaments, and truly isolated regions.The include nearly complete range morphological types spanning factor ∼ 10 luminosity star formation rate.The data consists images taken with the Advanced Camera Surveys...
The peculiar velocity of the Local Group galaxies manifested in Cosmic Microwave Background dipole is found to decompose into three dominant components. components are clearly separated because they arise on distinct spatial scales and fortuitously almost orthogonal their influences. nearest, which distinguished by a discontinuity at ~7 Mpc, arises from evacuation Void. We lie Sheet that bounds void. Random motions within small. Our Galaxy participates bulk motion away component our an...
We determine the intrinsic axial ratio distribution of 'gas' disks extremely faint M_B > -14.5 dwarf irregular galaxies. start with measured (beam corrected) apparent ratios in HI 21cm images galaxies observed as part Faint Irregular Galaxy GMRT Survey (FIGGS). Assuming that can be approximated oblate spheroids, obtained from distribution. use a couple methods to do this, and our final results are based on using Lucy's deconvolution algorithm. This method is constrained produce physically...
Cosmicflows-2 is a compilation of distances and peculiar velocities for over 8000 galaxies. Numerically the largest contributions come from luminosity–line width correlation spirals, Tully–Fisher relation (TFR), related fundamental plane E/S0 systems, but 1000 are contributed by methods that provide more accurate individual distances: Cepheid, tip red giant branch (TRGB), surface brightness fluctuation, Type Ia supernova, several miscellaneous procedures. Our collaboration making important...
We present an all-sky catalog of 869 nearby galaxies, having individual distance estimates within 11 Mpc or corrected radial velocities V_{LG} < 600 km/s. The is a renewed and expanded version the "Catalog Neighboring Galaxies" by Karachentsev et al. (2004). It collects data on following observables for galaxies: angular diameters, apparent magnitudes in FUV-, B-, K_s- bands, H_alpha HI fluxes, morphological types, HI-line widths, estimates. In this Local Volume (LV) sample 108 dwarf...
We present uniformly measured star formation histories (SFHs) of 60 nearby (D~4Mpc) dwarf galaxies based on CMDs resolved stellar populations from images taken with HST as part the ACS Nearby Galaxy Survey Treasury program (ANGST). This volume-limited sample contains 12 dSph/dE, 5 spiral, 28 dI, transition, and 3 tidal galaxies. From best fit SFHs we find three significant results: (1) average galaxy formed >50% its stars by z~2 60% z~1, regardless current morphological type; (2) mean dIs,...
We present Hubble Space Telescope/WFPC2 images of the galaxies NGC 2366, 2976, 4236, IC 2574, DDO 53, 82, 165, Holmberg I, II, IX, K52, K73, BK3N, Garland, and A0952+69 in M 81 complex. Their true distance moduli, derived from brightness tip red giant branch, lie range 2752 (NGC 2366) to 2830 (DDO 165), with a median 2791, which is typical for other known group members. Using distances radial velocities about 50 around 81/NGC 2403 complex, we find radius zero-velocity surface be ) Mpc,...
We present an analysis of Hubble Space Telescope/WFPC2 images nine nearby galaxies in Sculptor. derive their distances from the luminosity tip red giant branch stars with a typical accuracy ~ 12%. Their are 4.21 Mpc (Sc22), 4.92 (DDO226), 3.94 (NGC253), 3.40 (KDG2), 3.34 (DDO6), 3.42 (ESO540-030), 4.43 (ESO245-05), 4.27 (UGCA442), and 3.91 (NGC7793). The concentrated several spatially separated loose groups around NGC300, NGC253, NGC7793. Sculptor galaxy complex together CVn I cloud Local...
We present Hubble Space Telescope/WFPC2 images of seventeen dwarf galaxies in the Centaurus A group. Their distances derived from magnitudes tip red giant branch are 5.2 Mpc (KK112), 3.2 (ESO 321-014), 3.5 (KK179), 3.4 (NGC 5102), 4.6 (KK200), 3.7 324-024), 4.7 (KK208), 444-084), 4.4 (IC 4316), 4.5 5264), 3.6 (KK211), (KK213), 325-011), 3.8 (KK217), 4.0 (KK221), 4.8 5408), and (PGC 51659). The concentrated two spatially separated groups around NGC 5128 = Cen 5236 M 83. group itself has a...
Over the last few years, rapid progress has been made in distance measurements for nearby galaxies based on magnitude of tip red giant branch stars. Current CCD surveys with HST and large ground- telescopes bring $\sim$10%-accurate distances roughly a hundred within 5 Mpc. The new data to situated (and around) nearest groups: Local Group, M81 group, CenA/M83 IC342/Maffei Sculptor filament, Canes Venatici cloud allowed us determine their total mass from radius zero- velocity surface, $R_0$,...
We present HST/ACS images and color-magnitude diagrams for 24 nearby galaxies in near the constellation of Centaurus with radial velocities V_LG < 550 km/s. Distances are determined based on luminosities stars at tip red giant branch that range from 3.0 Mpc to 6.5 Mpc. The concentrated two spatially separated groups around Cen A (NGC 5128) M 83 5236). group itself has a mean distance 3.76 +/-0.05 Mpc, velocity dispersion 136 km/s, harmonic radius 192 kpc, an estimated orbital/virial mass...
We present an all-sky catalogue of 395 nearby galaxy groups revealed in the Local Supercluster and its surroundings. The their associations are identified among 10 914 galaxies at |b| > 15° with radial velocities VLG < 3500 km s−1. Our group-finding algorithm requires group members to be located inside zero-velocity surface. Hereby, we assume that individual masses proportional total K-band luminosities, M/LK= 6 M⊙/L⊙. sample our groups, where each has n≥ 4 members, is characterized by...
The Faint Irregular Galaxies GMRT Survey (FIGGS) is a Giant Metrewave Radio Telescope (GMRT) based HI imaging survey of systematically selected sample extremely faint nearby dwarf irregular galaxies. primary goal FIGGS to provide comprehensive and statistically robust characterization the neutral inter-stellar medium properties faint, gas rich galaxies represent low-mass end population, with median M${\rm{_B\sim-13.0}}$ mass $\sim 3 \times 10^7$ M$_\odot$, extending baseline in luminosity...
We present the unexpected discovery of four ultra diffuse galaxies (UDGs) in a group environment. recently identified seven extremely low surface brightness vicinity spiral galaxy M101, using data from Dragonfly Telephoto Array. The have effective radii $10"-38"$ and central brightnesses $25.6-27.7$ mag arcsec$^{-2}$ g-band. subsequently obtained follow-up observations with $HST$ to constrain distances these galaxies. Four remain persistently unresolved even spatial resolution $HST$/ACS,...
ABSTRACT We report the discovery of DGSAT I, an ultra-diffuse, quenched galaxy located 10.°4 in projection from Andromeda (M31). This low-surface brightness ( μ V = 24.8 mag arcsec −2 ), found with a small amateur telescope, appears unresolved sub-arcsecond archival Subaru/Suprime-Cam images, and hence has been missed by optical surveys relying on resolved star counts, spite its relatively large effective radius R e ) 12″) proximity (15′) to well-known dwarf spheroidal And II. Its red color...
We present new measurements of the abundance galaxies with a given circular velocity in Local Volume: region centered on Milky Way Galaxy and extending to distance 10Mpc. The sample 750 mostly dwarf provides unique opportunity study properties down absolute magnitudes MB= -10, virial masses Mvir= 1e9Msun. find that standard LCDM model gives remarkably accurate estimates for function velocities V>60kms corresponding Mvir> 3e10Msun, but it badly fails by over-predicting 5 times large dwarfs V=...
Abstract The tip of the red giant branch (TRGB) allows for measurement precise and accurate distances to nearby galaxies based on brightest ascent low-mass stars before they undergo helium flash. With advent JWST, there is great promise utilize technique measure galaxy out at least 50 Mpc, significantly further than Hubble Space Telescope's (HST's) reach 20 Mpc. However, with any standard candle, it first necessary provide an absolute reference. Here, we use Cycle 1 data calibration in F090W...
We consider a sample of 103 galaxies with radial velocities V_0_ < 500 km s^-1^ and distances obtained by means photometric distance indicators: Cepheids (n = 17), brightest stars 69), galaxy membership in the nearby bound groups 17). Ranking their R we determine running apex for Sun, Galaxy, Local Group as function R. For solar respect to LG obtain parameters: {l_sun_ 93^deg^+/-2^deg^, b_sun_ -4^deg^+/- 2^deg^, V_sun_ 316+/-5 s^-1^}. That corresponds Galaxy center {l 107^deg^, b -18^deg^, v...
The Hubble Space Telescope Advanced Camera for Surveys has been used to determine accurate distances 20 galaxies from measurements of the luminosity brightest red giant branch stars. Five associations dwarf that had originally identified based on strong correlations plane sky and in velocity are shown be equally well correlated distance. Two more with similar properties have discovered. Another association is suggested unbound through tidal disruption. spatial kinematic expected bound...
We present Hubble Space Telescope/WFPC2 images of sixteen dwarf galaxies as part our snapshot survey nearby galaxy candidates. derive their distances from the luminosity tip red giant branch stars with a typical accuracy ~12%. The resulting are 4.26 Mpc (KKH 5), 4.74 (KK 16), 4.72 17), 4.66 (ESO 115-021), 4.43 18), 3.98 27), 4.61 34), 4.99 54), 4.23 490-017), 4.90 (FG 202), 5.22 (UGC 3755), 5.18 3974), 4.51 65), 5.49 4115), 3.78 (NGC 2915), and 5.27 6503). Based on radial velocities 156...
We present Hubble Space Telescope/WFPC2 images of eighteen galaxies situated in the vicinity Local Group (LG) as part an ongoing snapshot survey nearby galaxies. Their distances derived from magnitude tip red giant branch are Mpc (ESO 294-010), (NGC 404), (UGCA 105), (Sex B), 3109), (UGC 6817), (KDG 90), (IC 3104), 7577), 8508), 8651), (KKH 86), 9240), (SagDIG), (DDO 210), 5152), 438), and 98). Based on velocity-distance data for 36 nearest around LG, we find radius zero-velocity surface LG...
To increase completeness of the distance limited sample nearby galaxies from Kraan-Korteweg & Tammann (1979) catalogue we undertook a search for small companions larger known which have corrected radial velocities within 500 km/s. Based primarely on POSS-II and ESO/SERC films found 260 dwarf galaxy candidates with angular diameters arcmin. More than 50% objects were revealed first time. As suppose, significant part them (about 30%) may really belong to Local Volume sample.