- ID:
- ivo://CDS.VizieR/J/ApJ/742/125
- Title:
- Galaxies in X-ray groups. I. COSMOS memberships
- Short Name:
- J/ApJ/742/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Understanding the mechanisms that lead dense environments to host galaxies with redder colors, more spheroidal morphologies, and lower star formation rates than field populations remains an important problem. As most candidate processes ultimately depend on host halo mass, accurate characterizations of the local environment, ideally tied to halo mass estimates and spanning a range in halo mass and redshift, are needed. In this work, we present and test a rigorous, probabilistic method for assigning galaxies to groups based on precise photometric redshifts and X-ray-selected groups drawn from the COSMOS field. The groups have masses in the range 10^13^<~M_200c_/M_{sun}_<~10^14^ and span redshifts 0<z<1. We characterize our selection algorithm via tests on spectroscopic subsamples, including new data obtained at the Very Large Telescope, and by applying our method to detailed mock catalogs. We find that our group member galaxy sample has a purity of 84% and completeness of 92% within 0.5R_200c_. We measure the impact of uncertainties in redshifts and group centering on the quality of the member selection with simulations based on current data as well as future imaging and spectroscopic surveys. As a first application of our new group member catalog which will be made publicly available, we show that member galaxies exhibit a higher quenched fraction compared to the field at fixed stellar mass out to z~1, indicating a significant relationship between star formation and environment at group scales. We also address the suggestion that dusty star-forming galaxies in such groups may impact the high-l power spectrum of the cosmic microwave background and find that such a population cannot explain the low power seen in recent Sunyaev-Zel'dovich measurements.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/142/65
- Title:
- Galaxies morphology and IR photometry III.
- Short Name:
- J/A+AS/142/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared H-band (1.65{mu}m) surface photometry of 558 galaxies in the Coma Supercluster and in the Virgo cluster. This data set, obtained with the Arcetri NICMOS3 camera ARNICA mounted on the Gornergrat Infrared Telescope, is aimed at complementing, with observations of mostly early-type objects, our NIR survey of spiral galaxies in these regions, presented in previous papers of this series. Magnitudes at the optical radius, total magnitudes, isophotal radii and light concentration indices are derived. We confirm the existence of a positive correlation between the near-infrared concentration index and the galaxy H-band luminosity
- ID:
- ivo://CDS.VizieR/J/A+AS/142/73
- Title:
- Galaxies morphology and IR photometry IV.
- Short Name:
- J/A+AS/142/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared (H band) surface photometry of 170 galaxies, obtained in 1997 using the Calar Alto 2.2 m telescope equipped with the NICMOS3 camera MAGIC. The majority of our targets are selected among bright members of the Virgo cluster, however galaxies in the A262 and Cancer clusters and in the Coma/A1367 supercluster are also included. This data set is aimed at complementing the NIR survey in the Virgo cluster discussed in Boselli et al. (1997A&A...324L..13B) and in the Coma Supercluster, presented in Papers I, II and III of this series. Magnitudes at the optical radius, total magnitudes, isophotal radii and light concentration indices are derived.
- ID:
- ivo://CDS.VizieR/J/A+A/361/863
- Title:
- Galaxies morphology and IR photometry. V.
- Short Name:
- J/A+A/361/863
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared H-band (1.65{mu}m) surface brightness profile decomposition for 1157 galaxies in five nearby clusters of galaxies: Coma, A1367, Virgo, A262 and Cancer, and in the bridge between Coma and A1367 in the "Great Wall". The optically selected (m_pg_<=16.0) sample is representative of all Hubble types, from E to Irr+BCD, except dE and of significantly different environments, spanning from isolated regions to rich clusters of galaxies. We model the surface brightness profiles with a de Vaucouleurs r^1/4^ law (dV), with an exponential disk law (E), or with a combination of the two (B+D). From the fitted quantities we derive the H band effective surface brightness ({mu}_e_) and radius (r_e_) of each component, the asymptotic magnitude H_T_ and the light concentration index C_31_. We find that: i) Less than 50% of the Elliptical galaxies have pure dV profiles. The majority of E to Sb galaxies is best represented by a B+D profile. All Scd to BCD galaxies have pure exponential profiles. ii) The type of decomposition is a strong function of the total H band luminosity (mass), independent of the Hubble classification: the fraction of pure exponential decompositions decreases with increasing luminosity, that of B+D increases with luminosity. Pure dV profiles are absent in the low luminosity range L_H_<10^10^L_{sun}_ and become dominant above 10^11^L_{sun}_.
- ID:
- ivo://CDS.VizieR/J/MNRAS/332/422
- Title:
- Galaxies morphology and IR photometry. VIII
- Short Name:
- J/MNRAS/332/422
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the distribution of a statistical sample of nearby galaxies in the {kappa}-space ({kappa1}{prop.to}logM, {kappa}2{prop.to}log(Ie)^3^*M/L, {kappa}3{prop.to}M/L). Our study is based on near-IR (H-band: {lamdba}=1.65{mu}m) observations, for the first time comprising early- and late-type systems. Our data confirm that the mean effective dynamical mass-to-light ratio M/L of the E+S0+S0a galaxies increases with increasing effective dynamical mass M, as expected from the existence of the Fundamental Plane relation. Conversely, spiral and Im/BCD galaxies show broad distribution in M/L with no detected trend of M/L with M, the former galaxies having M/L values about twice larger than the latter, on average. For all the late-type galaxies, the M/L increases with decreasing effective surface intensity Ie, consistent with the existence of the Tully-Fisher relation.
- ID:
- ivo://CDS.VizieR/J/ApJ/790/76
- Title:
- Galaxies near NGC 891 properties
- Short Name:
- J/ApJ/790/76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a survey of the region within 40 arcmin of NGC 891, a nearby nearly perfectly edge-on spiral galaxy. Candidate "non-stars" with diameters greater than 15 arcsec were selected from the GSC 2.3.2 catalog and cross-comparison of observations in several bands using archived GALEX, DSS2, WISE, and Two Micron All Sky Survey images identified contaminating stars, artifacts, and background galaxies, all of which were excluded. The resulting 71 galaxies, many of which were previously uncataloged, comprise a size-limited survey of the region. A majority of the galaxies are in the background of NGC 891 and are for the most part members of the A347 cluster at a distance of about 75 Mpc. The new finds approximately double the known membership of A347, previously thought to be relatively sparse. We identify a total of seven dwarf galaxies, most of which are new discoveries. The newly discovered dwarf galaxies are dim and gas-poor and may be associated with the previously observed arcs of red giant branch halo stars in the halo and the prominent H I filament and the lopsided features in the disk of NGC 891. Several of the dwarfs show signs of disruption, consistent with being remnants of an ancient collision.
1157. Galaxies near S1189
- ID:
- ivo://CDS.VizieR/J/MNRAS/406/2578
- Title:
- Galaxies near S1189
- Short Name:
- J/MNRAS/406/2578
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present radio images of a sample of six wide-angle tail (WAT) radio sources, identified in the Australia Telescope Large Area Survey 1.4-GHz radio survey, and new spectroscopic redshifts for four of these sources. These WATs are in the redshift range of 0.1469-0.3762, and we find evidence of galaxy overdensities in the vicinity of four of the WATs from either spectroscopic or photometric redshifts. We also present follow-up spectroscopic observations of the area surrounding the largest WAT, S1189, which is at a redshift of ~0.22. The spectroscopic observations, taken using the AAOmega spectrograph on the Anglo-Australian Telescope, show an overdensity of galaxies at this redshift. The galaxies are spread over an unusually large area of ~12Mpc with a velocity spread of ~4500km/s. This large-scale structure includes a highly asymmetric Fanaroff-Riley type I radio galaxy and also appears to host a radio relic. It may represent an unrelaxed system with different sub-structures interacting or merging with one another. We discuss the implications of these observations for future large-scale radio surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/514/A60
- Title:
- Galaxies of J0454-0309 lensing fossil group
- Short Name:
- J/A+A/514/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have discovered a strong lensing fossil group (J0454) projected near the well-studied cluster MS0451-0305. Using the large amount of available archival data, we compare J0454 to normal groups and clusters. A highly asymmetric image configuration of the strong lens enables us to study the substructure of the system. We used multicolour Subaru/Suprime-Cam and CFHT/Megaprime imaging, together with Keck spectroscopy to identify member galaxies. A VLT/FORS2 spectrum was taken to determine the redshifts of the brightest elliptical and the lensed arc. Using HST/ACS images, we determined the group's weak lensing signal and modelled the strong lens system. This is the first time that a fossil group is analysed with lensing methods. The X-ray luminosity and temperature were derived from XMM-Newton data.
- ID:
- ivo://CDS.VizieR/J/AJ/132/514
- Title:
- Galaxies of RX J1416.4+2315 cluster
- Short Name:
- J/AJ/132/514
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the properties of the fossil cluster RX J1416.4+2315 through g'- and i'-band imaging and spectroscopy of 25 member galaxies. The system is at a mean redshift of 0.137 and has a velocity dispersion of 584km/s. Superposed onto one quadrant of the cluster field is a group of five galaxies at a mean redshift of 0.131, which, if included as part of the cluster, increases the velocity dispersion to 846km/s. The central object of RX J1416.4+2315 is a normal elliptical galaxy with no cD envelope.
- ID:
- ivo://CDS.VizieR/J/A+A/573/A93
- Title:
- Galaxies optical emission-line diagnostic diagrams
- Short Name:
- J/A+A/573/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The discovery of the M-{sigma} relation, the local galaxy bimodality, and the link between black-hole and host-galaxy properties have raised the question of whether active galactic nuclei (AGN) play a role in galaxy evolution. AGN feedback is one of the biggest observational challenges of modern extragalactic astrophysics. Several theoretical models implement AGN feedback to explain the observed galaxy luminosity function and, possibly, the color and morphological transformation of spiral galaxies into passive ellipticals. For understanding the importance of AGN feedback, a study of the AGN populations in the radio-optical domain is crucial. A mass sequence linking star-forming galaxies and AGN has already been noted in previous works, and it is now investigated as a possible evolutionary sequence. We observed a sample of 119 intermediate-redshift (0.04<=z<0.4) SDSS-FIRST radio emitters with the Effelsberg 100-m telescope at 4.85 and 10.45GHz and obtained spectral indices. The sample includes star-forming galaxies, composite galaxies (with mixed contribution to line emission from star formation and AGN activity), Seyferts, and low ionization narrow emission region (LINER) galaxies. With these sources we search for possible evidence of spectral evolution and a link between optical and radio emission in intermediate-redshift galaxies. We find indications of spectral index flattening in high-metallicity star-forming galaxies, composite galaxies, and Seyferts. This "flattening sequence" along the [NII]-based emission-line diagnostic diagram is consistent with the hardening of galaxy ionizing field, thanks to nuclear activity. After combining our data with FIRST measurements at 1.4GHz, we find that the three-point radio spectra of Seyferts and LINERs show substantial differences, which are attributable to small radio core components and larger (arcsecond sized) jet/lobe components, respectively. A visual inspection of FIRST images seems to confirm this hypothesis. Galaxies along this sequence are hypothesized to be transitioning from the active star-forming galaxies (blue cloud) to the passive elliptical galaxies (red sequence). This supports the suggestion that AGN both play a role in shutting down star formation and allow the transition from one galaxy class to the other.
