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...

The luminosity of the Tip Red Giant Branch (TRGB) provides an excellent measure galaxy distances and is easily determined in resolved images nearby galaxies observed with Hubble Space Telescope. There now a large amount archival data relevant to TRGB methodology which offers comparisons other distance estimators. Zero-point issues related scale are reviewed this paper. Consideration given metallicity dependence TRGB, transformations between HST flight systems Johnson-Cousins photometry,...

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...

Accurate distances to galaxies can be determined from the luminosities of stars at tip red giant branch (TRGB). We use a maximum likelihood algorithm locate TRGB in galaxy color-magnitude diagrams. The is optimized by introducing reliable photometric errors and completeness characterization with artificial star experiments. program extensively tested using Monte Carlo simulations, galaxies, sample nearby dwarf observed Hubble Space Telescope WFPC2 ACS. Our procedure shown reliable, have good...

The CMDs/TRGB (Color-Magnitude Diagrams/Tip of the Red Giant Branch) section Extragalactic Distance Database contains a compilation observations nearby galaxies from Hubble Space Telescope. Approximately 250 (and increasing) in Local Volume have CMDs and stellar photometry tables used to produce them available through web. Various populations that make up galaxy are visible CMDs, but our primary purpose for collecting analyzing these images is measure TRGB each. We can estimate distance by...

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 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...

Abstract The Virgo Cluster is the nearest substantial cluster of galaxies to Milky Way and a cornerstone extragalactic distance scale. Here, we present JWST/NIRCam observations that simultaneously cover cores halos 10 in around are designed perform simultaneous measurements tip red giant branch (TRGB) surface brightness fluctuations (SBF). Seven targets within where able resolve some cluster’s substructure, while an additional three provide important constraints on infall. seven itself all...

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 Advanced Camera for Surveys images and color-magnitude diagrams 25 nearby galaxies with radial velocities VLG < 500 km s-1. Distances are determined based on the luminosities of stars at tip red giant branch that range from 2 to 12 Mpc. Two galaxies, NGC 4163 IC 4662, found be nearest known representatives blue compact dwarf objects. Using high-quality data distances 110 field we derive their mean ratio 68 s-1 Mpc-1 a standard deviation 15 Mpc-1. Peculiar...

Context. Now that modern imaging surveys have produced large databases of galaxy images advanced morphological studies become possible. This has driven the need for well-defined calibration samples.

We obtained follow-up HST observations of the seven low surface brightness galaxies discovered with Dragonfly Telephoto Array in field massive spiral galaxy M101. Out galaxies, only three were resolved into stars and are potentially associated M101 group at $D=7\text{ Mpc}$. Based on ACS photometry broad F606W F814W filters, we use a maximum likelihood algorithm to locate Tip Red Giant Branch (TRGB) color-magnitude diagrams. Distances $6.38^{+0.35}_{-0.35}, 6.87^{+0.21}_{-0.30}$...

Abstract Differences between the local value of Hubble constant measured via distance ladder versus inferred from cosmic microwave background with assumption standard ΛCDM model have reached over 5 σ significance. To determine if this discrepancy is due to new physics or more mundane systematic errors, it essential remove as many sources uncertainty possible, by developing high-precision ladders that are independent traditional Cepheid and Type Ia supernova route. Here, we present JWST...

We derive quantitative star formation histories of the four suspected tidal dwarf galaxies in M 81 group, Holmberg IX, BK3N, Arp-loop (A0952+69), and Garland, using Hubble Space Telescope/Wide Field Planetary Camera 2 images F606W F814W obtained as part a Snapshot survey Local Universe. consider spatial distribution ages resolved stellar populations these irregular galaxies. use synthetic color-magnitude diagrams to major episodes, rates, approximate metallicity ranges. All show evidence...

Abstract We present surface photometry and metallicity measurements for 104 nearby dwarf galaxies imaged with the Advanced Camera Surveys Wide Field Planetary 2 aboard Hubble Space Telescope. In addition, we carried out 26 of sample Sextans B on images Sloan Digital Sky Survey. Our comprises spheroidal, irregular transition type located within ∼10 Mpc in field groups: M81, Centaurus A, Sculptor Canes Venatici I cloud. It is found that early-type have average higher at a given luminosity...

Context. In recent years, a new generation of large-scale imaging surveys have probed wide field regions for the first time around some nearby galaxies in an unprecedentedly low surface-brightness regime (∼28.0−29.0 mag arcsec −2 ). This provides chance to discover very faint dwarf satellites by means systematic visual inspection these public deep images. Aims. this paper, we report results survey spheroidal vicinity bright late-type spiral galaxy NGC 253 images taken Dark Energy Survey....

We present a photometric and spectroscopic study of the unique isolated nearby dwarf spheroidal (dSph) galaxy KKR 25. The was resolved into stars with Hubble Space Telescope/Wide Field Planetary Camera 2 including old red giant branch clump. have constructed model stellar populations measured star formation rate metallicity as function time. main activity period occurred about 12.6–13.7 Gyr ago. These are mostly metal poor, mean [Fe/H] ∼ −1 to −1.6 dex. About 60 per cent total mass formed...

Hubble Space Telescope Advanced Camera for Surveys has been used to determine accurate distances the spiral galaxy NGC2683 and 12 other galaxies in a zone of "local velocity anomaly" from measurements luminosities brightest red giant branch stars. These lie Leo Spur, nearest filament beyond our home Local Sheet. The new, distance confirm that along Spur are more distant than expected uniform cosmic expansion, hence have large peculiar velocities toward us. motions generally explained by...

Dwarf galaxies provide a unique opportunity for studying the evolution of Milky Way (MW) and Local Group as whole. Analysing running solar apex based on kinematics MW satellites, we discovered an unexpected behaviour dipole term radial velocity distribution function galactocentric distance. The nearby satellites (<100 kpc) have bulk motion with amplitude 140-230 km/s while more distant ones show isotropic velocities. Such strong variations can not be explained by net rotation it would...

We analyze the velocity field of peripheral members Local Group. The Hubble flow at distances from 400 to 1400 kpc, formed by 7 11 nearby galaxies, is characterized an extremely small line-of-sight dispersion 15 which differs significantly predictions cosmological simulations about 70 . This fact allows us determine total mass Group as M_ LG = (2.47 ± 0.15) using analytical model around a spherical overdensity in standard flat Universe. practical equality this sum masses our Galaxy and...

Observations of 39 nearby, mostly dwarf galaxies are presented. The observations were carried out at the 1.2-m telescope Observatoire de Haute-Provence (France) with and I Cousins filters. Based on surface integrated photometry obtained images we derived total magnitudes , colours as well radii 25m isophotal level. Azimuthally averaged brightness profiles for 33 in each photometric band. Most can be fitted by an exponential intensity law distribution. best-fitting parameters also given galaxies.

Abstract Observations of the highly isolated dwarf spheroidal galaxy KKs 3 = [KK2000] 03 with Hubble Space Telescope Advanced Camera for Surveys are presented. We measured distance 2.12 ± 0.07 Mpc using tip red giant branch method. The total blue absolute magnitude is estimated as MB −10.8 mag. briefly discuss star formation history derived from its colour–magnitude diagram. According to our calculation, stellar mass 2.3 × 107 M⊙, and most stars (74 per cent) were formed at an early epoch...

We present a catalogue of 16551 edge-on galaxies created using the public DR2 data Pan-STARRS survey. The covers three quarters sky above Dec.=-30 degrees. were selected convolutional neural network, trained on sample identified earlier in SDSS This approach allows us to dramatically improve quality candidate selection and perform thorough visual inspection reasonable amount time. provides homogeneous information astrometry, SExtractor photometry, non-parametric morphological statistics...

In the Canes Venatici cloud, eighteen dwarf irregular galaxies were observed in bands at Nordic Optical Telescope under a seeing of one arcsec. Most having radial velocities 500 km/s have been resolved into stars for first time. The galaxy distances derived based on photometry their brightest blue stars. Distances to some galaxies: UGC 6782, 7131 and, probably, K 215, which are located CVn southern edge, estimated be about 15 Mpc, is typical Virgo cluster outskirts. For two LSB galaxies, 200...

The paper presents new results of the ongoing study unusual Lynx-Cancer void galaxy DDO 68 with record-low-metallicity regions (12+log(O/H) ~7.14) current star formation (SF). They include: a) a spectrum and photometry 6-m SAO RAS telescope (BTA) for Luminous Blue Variable (LBV = DDO68-V1). Photometric data sets are complemented those based on Sloan Digital Sky Survey (SDSS) Hubble Space Telescope (HST) archive images; b) analysis DDO~68 supergiant shell (SGS) prominent smaller H-alpha...