- ID:
- ivo://CDS.VizieR/J/AJ/109/543
- Title:
- Color of Bright Galaxies
- Short Name:
- J/AJ/109/543
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Total color indices (V-R)tot, (V-I)tot and effective color indices (V-R)eff, (V-I)eff in the Cousins VRI photometric system are presented for 501 mostly normal galaxies. The colors are computed using a procedure outlined in the Third Reference Catalogue of Bright Galaxies (RC3) whereby standard color curves approximated by Laplace-Gauss integrals are fitted to observed photoelectric multiaperture photometry. 11 sources of such photometry were used for our analysis, each source being assigned an appropriate weight according to a rigorous analysis of residuals of the data from the best-fitting standard color curves. Together with the integrated B-V and U-B colors provided in RC3, our analysis widens the range of wavelength of homogeneously defined colors of normal galaxies of all Hubble types. We present color-color and color-type relations that can be modeled to understand the star formation history of galaxies.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/883/78
- Title:
- Column densities of CGM absorption lines
- Short Name:
- J/ApJ/883/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the geometric distribution of gas metallicities in the circumgalactic medium (CGM) around 47, z<0.7 galaxies from the "Multiphase Galaxy Halos" Survey. Using a combination of quasar spectra from Hubble Space Telescope (HST)/COS and from Keck/HIRES or Very Large Telescope/UVES, we measure column densities of, or determine limits on, CGM absorption lines. We then use a Markov Chain Monte Carlo approach with Cloudy to estimate the metallicity of cool (T~10^4^K) CGM gas. We also use HST images to determine host-galaxy inclination and quasar-galaxy azimuthal angles. Our sample spans a HI column density range of 13.8cm^-2^<logN_HI_<19.9cm^-2^. We find (1) while the metallicity distribution appears bimodal, a Hartigan dip test cannot rule out a unimodal distribution (0.4{sigma}). (2) CGM metallicities are independent of halo mass, spanning three orders of magnitude at a fixed halo mass. (3) The CGM metallicity does not depend on the galaxy azimuthal and inclination angles regardless of HI column density, impact parameter, and galaxy color. (4) The ionization parameter does not depend on azimuthal angle. We suggest that the partial Lyman limit metallicity bimodality is not driven by a spatial azimuthal bimodality. Our results are consistent with simulations where the CGM is complex and outflowing, accreting, and recycled gas are well-homogenized at z<0.7. The presence of low-metallicity gas at all orientations suggests that cold streams of accreting filaments are not necessarily aligned with the galaxy plane at low redshifts or intergalactic transfer may dominate. Finally, our results support simulations showing that strong metal absorption can mask the presence of low-metallicity gas in integrated line-of-sight CGM metallicities.
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/4336
- Title:
- Coma galaxies UV and opt. view
- Short Name:
- J/MNRAS/478/4336
- Date:
- 10 Dec 2021 00:56:54
- Publisher:
- CDS
- Description:
- The Coma supercluster (100h^-1^Mpc) offers an unprecedented contiguous range of environments in the nearby Universe. In this paper, we present a catalogue of spectroscopically confirmed galaxies in the Coma supercluster detected in the ultraviolet (UV) wavebands. We use the arsenal of UV and optical data for galaxies in the Coma supercluster covering ~500deg^2^ on the sky to study their photometric and spectroscopic properties as a function of environment at various scales. We identify the different components of the cosmic-web: large-scale filaments and voids using Discrete Persistent Structures Extractor, and groups and clusters using Hierarchical Density-based spatial clustering of applications with noise, respectively. We find that in the Coma supercluster the median emission in H{alpha} inclines, while the g-r and FUV-NUV colours of galaxies become bluer moving further away from the spine of the filaments out to a radius of ~1Mpc. On the other hand, an opposite trend is observed as the distance between the galaxy and centre of the nearest cluster or group decreases. Our analysis supports the hypothesis that properties of galaxies are not just defined by its stellar mass and large-scale density, but also by the environmental processes resulting due to the intrafilament medium whose role in accelerating galaxy transformations needs to be investigated thoroughly using multiwavelength data.
- ID:
- ivo://CDS.VizieR/J/ApJ/720/723
- Title:
- Compact galaxies in the local universe
- Short Name:
- J/ApJ/720/723
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We set out to test the claim that the recently identified population of compact, massive, and quiescent galaxies at z~2.3 must undergo significant size evolution to match the properties of galaxies found in the local universe. Using data from the Sloan Digital Sky Survey (SDSS; Data Release 7), we have conducted a search for local red sequence galaxies with sizes and masses comparable to those found at z~2.3. The SDSS spectroscopic target selection algorithm excludes high surface brightness objects; we show that this makes incompleteness a concern for such massive, compact galaxies, particularly for low redshifts (z<~0.05). We have identified 63 M_*_>10^10.7^M_{sun}_ (~5x10^10^M_{sun}_) red sequence galaxies at 0.066<z_spec_<0.12 which are smaller than the median size-mass relation by a factor of 2 or more. Consistent with expectations from the virial theorem, the median offset from the mass-velocity dispersion relation for these galaxies is 0.12 dex. We do not, however, find any galaxies with sizes and masses comparable to those observed at z~2.3, implying a decrease in the comoving number density of these galaxies, at fixed size and mass, by a factor of >~5000. This result cannot be explained by incompleteness: in the 0.066<z<0.12 interval, we estimate that the SDSS spectroscopic sample should typically be >~75% complete for galaxies with the sizes and masses seen at high redshift, although for the very smallest galaxies it may be as low as ~20%. In order to confirm that the absence of such compact massive galaxies in SDSS is not produced by spectroscopic selection effects, we have also looked for such galaxies in the basic SDSS photometric catalog, using photometric redshifts. While we do find signs of a slight bias against massive, compact galaxies, this analysis suggests that the SDSS spectroscopic sample is missing at most a few objects in the regime we consider.
- ID:
- ivo://CDS.VizieR/J/ApJS/225/23
- Title:
- Compact groups of galaxies from SDSS-DR12 (MLCG)
- Short Name:
- J/ApJS/225/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We apply a friends-of-friends algorithm to an enhanced SDSS DR12 spectroscopic catalog, including redshift from the literature to construct a catalog of 1588 N>=3 compact groups of galaxies containing 5178 member galaxies and covering the redshift range 0.01<z<0.19. This catalog contains 18 times as many systems and reaches 3 times the depth of the similar catalog of Barton et al. (1996AJ....112..871B). We construct catalogs from both magnitude-limited and volume-limited galaxy samples. Like Barton et al. we omit the frequently applied isolation criterion in the compact group selection algorithm. Thus the groups selected by fixed projected spatial and rest-frame line-of-sight velocity separation produce a catalog of groups with a redshift-independent median size. In contrast to previous catalogs, the enhanced SDSS DR12 catalog (including galaxies with r<14.5) includes many systems with z<~0.05. The volume-limited samples are unique to this study. The compact group candidates in these samples have a median stellar mass independent of redshift. Groups with velocity dispersion <~100km/s show abundant evidence for ongoing dynamical interactions among the members. The number density of the volume-limited catalogs agrees with previous catalogs at the lowest redshifts but decreases as the redshift increases. The SDSS fiber placement constraints limit the catalog's completeness. In spite of this issue, the volume-limited catalogs provide a promising basis for detailed spatially resolved probes of the impact of galaxy-galaxy interactions within similar dense systems over a broad redshift range.
- ID:
- ivo://CDS.VizieR/J/ApJS/246/12
- Title:
- Compact groups of galaxies in SDSS & LAMOST. I.
- Short Name:
- J/ApJS/246/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A compact group (CG) is a kind of special galaxy system where the galaxy members are separated at distances of the order of galaxy size. The strong interaction between the galaxy members makes CGs ideal labs for studying the environmental effects on galaxy evolution. The traditional photometric selection algorithm biases against the CG candidates at low redshifts, while the spectroscopic identification technique is affected by the spectroscopic incompleteness of sample galaxies and typically biases against the high redshift candidates. In this study, we combine these two methods and select CGs in the main galaxy sample of the Sloan Digital Sky Survey, where we also have taken the advantages of the complementary redshift measurements from the LAMOST spectral and GAMA surveys. We have obtained the largest and most complete CG samples to date. Our samples include 6144 CGs and 8022 CG candidates, which are unique in the studies of the nature of the CGs and the evolution of the galaxies inside.
- ID:
- ivo://CDS.VizieR/J/ApJ/886/124
- Title:
- Completed KMOS^3D^ survey NIR obs.
- Short Name:
- J/ApJ/886/124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the completed KMOS^3D^ survey, an integral field spectroscopic survey of 739 log(M_*_/M_{sun}_)>9 galaxies at 0.6<z<2.7 using the K-band Multi Object Spectrograph (KMOS) at the Very Large Telescope. The KMOS3D survey provides a population-wide census of kinematics, star formation, outflows, and nebular gas conditions both on and off the star-forming galaxy main sequence through the spatially resolved and integrated properties of H{alpha}, [NII], and [SII] emission lines. We detect H{alpha} emission for 91% of galaxies on the main sequence of star formation and 79% overall. The depth of the survey has allowed us to detect galaxies with star formation rates below 1M_{sun}_/yr, as well as to resolve 81% of detected galaxies with >=3 resolution elements along the kinematic major axis. The detection fraction of H{alpha} is a strong function of both color and offset from the main sequence, with the detected and nondetected samples exhibiting different spectral energy distribution shapes. Comparison of H{alpha} and UV+IR star formation rates reveal that dust attenuation corrections may be underestimated by 0.5dex at the highest masses (log(M_*_/M_{sun}_)>10.5). We confirm our first year results of a high rotation-dominated fraction (monotonic velocity gradient and v_rot_/{sigma}_0_>3.36^0.5^) of 77% for the full KMOS^3D^ sample. The rotation-dominated fraction is a function of both stellar mass and redshift, with the strongest evolution measured over the redshift range of the survey for galaxies with log(M_*_/M_{sun}_)<10.5.
- ID:
- ivo://CDS.VizieR/J/ApJ/849/20
- Title:
- Contents of RESOLVE & ECO galaxy groups
- Short Name:
- J/ApJ/849/20
- Date:
- 18 Nov 2021 00:26:09
- Publisher:
- CDS
- Description:
- We examine the z=0 group-integrated stellar and cold baryonic (stars + cold atomic gas) mass functions (group SMF and CBMF) and the baryonic collapse efficiency (group cold baryonic to dark matter halo mass ratio) using the RESOLVE and ECO survey galaxy group catalogs and a GALFORM semi-analytic model (SAM) mock catalog. The group SMF and CBMF fall off more steeply at high masses and rise with a shallower low-mass slope than the theoretical halo mass function (HMF). The transition occurs at the group-integrated cold baryonic mass M_bary_^cold^~10^11^M_{sun}_. The SAM, however, has significantly fewer groups at the transition mass ~10^11^M_{sun}_ and a steeper low-mass slope than the data, suggesting that feedback is too weak in low-mass halos and conversely too strong near the transition mass. Using literature prescriptions to include hot halo gas and potential unobservable galaxy gas produces a group BMF with a slope similar to the HMF even below the transition mass. Its normalization is lower by a factor of ~2, in agreement with estimates of warm-hot gas making up the remaining difference. We compute baryonic collapse efficiency with the halo mass calculated two ways, via halo abundance matching (HAM) and via dynamics (extended all the way to three-galaxy groups using stacking). Using HAM, we find that baryonic collapse efficiencies reach a flat maximum for groups across the halo mass range of M_halo_~10^11.4-12^M_{sun}_, which we label "nascent groups". Using dynamics, however, we find greater scatter in baryonic collapse efficiencies, likely indicating variation in group hot-to-cold baryon ratios. Similarly, we see higher scatter in baryonic collapse efficiencies in the SAM when using its true groups and their group halo masses as opposed to friends-of-friends groups and HAM masses.
- ID:
- ivo://CDS.VizieR/J/ApJ/866/133
- Title:
- Continuum-H{beta} light curves of 5 Seyfert 1
- Short Name:
- J/ApJ/866/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from a reverberation-mapping campaign undertaken during the first half of 2012, with additional data on one active galactic nucleus (AGN) (NGC 3227) from a 2014 campaign. Our main goals are (1) to determine the black hole masses from continuum-H{beta} reverberation signatures, and (2) to look for velocity-dependent time delays that might be indicators of the gross kinematics of the broad-line region. We successfully measure H{beta} time delays and black hole masses for five AGNs, four of which have previous reverberation mass measurements. The values measured here are in agreement with earlier estimates, though there is some intrinsic scatter beyond the formal measurement errors. We observe velocity-dependent H{beta} lags in each case, and find that the patterns have changed in the intervening five years for three AGNs that were also observed in 2007.
- ID:
- ivo://CDS.VizieR/J/A+A/562/A24
- Title:
- Cool carbon stars in the halo and Fornax dSph
- Short Name:
- J/A+A/562/A24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The population of cool carbon (C) stars located far from the galactic plane is probably made of debris of small galaxies such as the Sagittarius dwarf spheroidal galaxy (Sgr), which are disrupted by the gravitational field of the Galaxy. We aim to know this population better through spectroscopy, 2MASS photometric colours, and variability data. When possible, we compared the halo results to C star populations in the Fornax dwarf spheroidal galaxy, Sgr, and the solar neighbourhood. We first present a few new discoveries of C stars in the halo and in Fornax. The number of spectra of halo C stars is now 125. Forty percent show H{alpha} in emission. The narrow location in the JHK diagram of the halo C stars is found to differ from that of similar C stars in the above galaxies. The light curves of the Catalina and LINEAR variability databases were exploited to derive the pulsation periods of 66 halo C stars. A few supplementary periods were obtained with the TAROT telescopes. We confirm that the period distribution of the halo strongly resembles that of Fornax, and we found that it is very different from the C stars in the solar neighbourhood. There is a larger proportion of short-period Mira/SRa variables in the halo than in Sgr, but the survey for C stars in this dwarf galaxy is not complete, and the study of their variability needs to be continued to investigate the link between Sgr and the cool halo C stars.