- ID:
- ivo://CDS.VizieR/J/ApJ/853/47
- Title:
- Brightest cluster galaxies bright in 22um (W4BCGs)
- Short Name:
- J/ApJ/853/47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Brightest cluster galaxies (BCGs) are believed to have assembled most of their stars early in time and therefore should be passively evolving at low redshifts and appear "red-and-dead." However, there have been reports that a minority of low-redshift BCGs still have ongoing star formation rates (SFRs) of a few to even ~100M_{sun}_/yr. Such BCGs are found in "cool-core" ("CC") clusters, and their star formation is thought to be fueled by "cooling flow." To further investigate the implications of low-redshift, star-forming BCGs, we perform a systematic search using the 22{mu}m data ("W4" band) from the Wide-field Infrared Survey Explorer (WISE) on the GMBCG catalog, which contains 55424 BCGs at 0.1<~z<~0.55 identified in the Sloan Digital Sky Survey (SDSS). Our sample consists of 389 BCGs that are bright in W4 ("W4BCGs"), most being brighter than 5mJy. While some (<~20%) might host active galactic nuclei, most W4BCGs should owe their strong mid-IR emissions to dust-enshrouded star formation. Their median total IR luminosity (L_IR_) is 5x10^11^L_{sun}_ (SFR~50M_{sun}_/yr), and 27% of the whole sample has L_IR_>10^12^L_{sun}_ (SFR>100M_{sun}_/yr). Using 10 W4BCGs that have Chandra X-ray data, we show that 7 of them are possibly in CC clusters. However, in most cases (five out of seven) the mass deposition rate cannot account for the observed SFR. This casts doubt on the idea that cooling flows are the cause of the star formation in non-quiescent BCGs.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/405
- Title:
- Brightest galaxies in Local Volume
- Short Name:
- J/MNRAS/440/405
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Distances and near-infrared luminosities of the brightest galaxies in the Local Volume have been re-evaluated in order to gain a fully homogeneous collection of data for elucidating the framework of the Local Sheet and its relevance to Local Group evolution. It is demonstrated that the Local Sheet is both geometrically and dynamically distinct from the Local Supercluster and that the evolution of the Sheet and Local Group were probably interconnected. The Sheet is inclined by 8{deg} with respect to the Local Supercluster, and the dispersion of giant members about the mid-plane is only 230kpc. A 'Council of Giants' with a radius of 3.75Mpc encompasses the Local Group, demarcating a clear upper limit to the realm of influence of the Local Group. The only two giant elliptical galaxies in the Sheet sit on opposite sides of the Council, raising the possibility that they have somehow shepherded the evolution of the Local Group. The position vector of the Andromeda galaxy with respect to the Milky Way deviates only 11{deg} from the Sheet plane and only 11{deg} from the projected axis of the ellipticals. The Local Group appears to be moving away from a ridge in the potential surface of the Council on a path parallel to the elliptical axis. Spin directions of the giants in the Council are distributed over the sky in a pattern which is very different from that of giants beyond, possibly in reaction to the central mass asymmetry that developed into the Local Group. By matching matter densities of Group and Council giants, the edge of the volume of space most likely to have contributed to the development of the Local Group is shown to be very close to where gravitational forces from the Local Group and the Council balance. The boundary specification reveals that the Local Sheet formed out of a density perturbation of very low amplitude (~10%), but that normal matter was incorporated into galaxies with relatively high efficiency (~40%). It appears that the development of the giants of the Local Sheet was guided by a pre-existing flattened framework of matter.
- ID:
- ivo://CDS.VizieR/J/ApJ/889/189
- Title:
- Brightest high-z galaxies in RELICS clusters
- Short Name:
- J/ApJ/889/189
- Date:
- 17 Jan 2022 00:21:16
- Publisher:
- CDS
- Description:
- Massive foreground galaxy clusters magnify and distort the light of objects behind them, permitting a view into both the extremely distant and intrinsically faint galaxy populations. We present here the z~6-8 candidate high-redshift galaxies from the Reionization Lensing Cluster Survey (RELICS), a Hubble and Spitzer Space Telescope survey of 41 massive galaxy clusters spanning an area of ~200arcmin^2^. These clusters were selected to be excellent lenses, and we find similar high-redshift sample sizes and magnitude distributions as the Cluster Lensing And Supernova survey with Hubble (CLASH). We discover 257, 57, and eight candidate galaxies at z~6, 7, and 8 respectively, (322 in total). The observed (lensed) magnitudes of the z~6 candidates are as bright as AB mag ~23, making them among the brightest known at these redshifts, comparable with discoveries from much wider, blank-field surveys. RELICS demonstrates the efficiency of using strong gravitational lenses to produce high-redshift samples in the epoch of reionization. These brightly observed galaxies are excellent targets for follow-up study with current and future observatories, including the James Webb Space Telescope.
- ID:
- ivo://CDS.VizieR/J/AJ/124/1954
- Title:
- 1000 brightest HIPASS galaxies catalog
- Short Name:
- J/AJ/124/1954
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The HI Parkes All-Sky Survey (HIPASS) is a blind 21cm survey for extragalactic neutral hydrogen, covering the whole southern sky. The HIPASS Bright Galaxy Catalog (BGC) is a subset of HIPASS and contains the 1000 HI brightest (peak flux density) galaxies. Here we present the 138 HIPASS BGC galaxies that had no redshift measured prior to the Parkes multibeam HI surveys. Of the 138 galaxies, 87 are newly catalogued. Newly catalogued is defined as having no optical (or infrared) counterpart in the NASA/IPAC Extragalactic Database. Using the Digitized Sky Survey, we identify optical counterparts for almost half of the newly catalogued galaxies, which are typically of irregular or Magellanic morphological type. Several HI sources appear to be associated with compact groups or pairs of galaxies rather than an individual galaxy. The majority (57) of the newly catalogued galaxies lie within 10{deg} of the Galactic plane and are missing from optical surveys as a result of confusion with stars or dust extinction. This sample also includes newly catalogued galaxies first discovered by Henning et al. in the HI shallow survey of the zone of avoidance. The other 30 newly catalogued galaxies escaped detection because of their low surface brightness or optical compactness. Only one of these, HIPASS J0546-68, has no obvious optical counterpart, as it is obscured by the Large Magellanic Cloud. We find that the newly catalogued galaxies with |b|>10{deg} are generally lower in HI mass and narrower in velocity width compared with the total HIPASS BGC. In contrast, newly catalogued galaxies behind the Milky Way are found to be statistically similar to the entire HIPASS BGC. In addition to these galaxies, the HIPASS BGC contains four previously unknown HI clouds. Description:
- ID:
- ivo://CDS.VizieR/J/MNRAS/216/173
- Title:
- Bright extragalactic radio sources at 2.7 GHz
- Short Name:
- J/MNRAS/216/173
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The brightest extragalactic radio sources at 2.7 GHz are catalogued. The complete sample comprises 233 sources found in the major centimeter wavelength surveys carried out at ANRAO/Parkes, NNRAO/Greenbank, and MPIfR/Bonn: the sample covers 9.81 sr and has limits S(27) = 2.0 Jy and |b| > 10{deg}. A critical reanalysis of the data shows that 227 (97 percent) have optical identifications and 171 (73 percent) have measured redshifts. The implications of the catalogue statistics for the luminosity functions of different radio-source populations are considered.
- ID:
- ivo://CDS.VizieR/VIII/5
- Title:
- Bright Extragalactic Radio Sources (1Jy)
- Short Name:
- VIII/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a compilation of 518 extragalactic radio sources with flux densities greater than 1 Jy at 5 GHz. It contains sources from the NRAO-MPI 5-GHz Strong Source Surveys and from re-observation at 5 GHz of sources found in the Parkes 2.7-GHz surveys. All sources were found in 9.811 sr covered by the two surveys. This is essentially the whole sky, excluding the galactic plane (latitudes less than 10 degrees) and the Magellanic Clouds. The catalog includes radio flux densities, radio positions, object classes, visual magnitudes, redshifts, and spectral indices.
- ID:
- ivo://CDS.VizieR/J/A+A/487/453
- Title:
- Bright galaxies in 5 medium redshift clusters. I.
- Short Name:
- J/A+A/487/453
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using data from five clusters of galaxies within the redshift range 0.15<=z<=0.25, imaged with the Nordic Optical Telescope (NOT) in the central ~1Mpc^2^ in very good seeing conditions, we have performed an exhaustive inspection of their bright galaxy population. That range of redshift, where only a small amount of data with the required resolution and quality is available, is particularly important for the understanding of the formation and evolution of clusters of galaxies. We have inspected the color-magnitude relation (CMR) for those clusters and measured the blue fraction of galaxies in their cores to check for evidence of evolution as found in other works. Visual classification of the galaxy morphology has been performed and the morphology-radius relation examined.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A159
- Title:
- Bright Lyman-alpha emitters in MUSE/COSMOS field
- Short Name:
- J/A+A/633/A159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We search for the presence of bright Ly-alpha emitters among Spitzer SMUVS galaxies at z>2.9 making use of homogeneous MUSE spectroscopic data. Although these data only cover a small region of COSMOS, MUSE has the unique advantage of providing spectral information over the entire field, without the need of target pre-selection. This results in an unbiased detection of all the brightest Ly-alpha emitters among the SMUVS sources, which by design are stellar-mass selected galaxies. Within the studied area, ~14% of the SMUVS galaxies at z>2.9 have Ly-alpha fluxes F_{lambda}_>~7x10^-18^erg/s/cm^2^. These Ly-alpha emitters are characterized by three types of emission, 47% show a single line profile, 19% present a double peak or a blue bump and 31% show a red tail. One object (3%) shows both a blue bump and a red tail. We also investigate the spectral energy distribution (SED) properties of the SMUVS galaxies which are MUSE detected and which are not. After stellar-mass matching both populations, we find that the MUSE detected galaxies have generally lower extinction than SMUVS-only objects, while there is no clear intrinsic difference in the mass and age distributions of the two samples. For the MUSE-detected SMUVS galaxies, we compare the instantaneous SFR lower limit obtained from the Ly-alpha line with its past average derived from SED fitting, and find evidence for rejuvenation in some of our oldest objects. In addition, we study the spectra of those Ly-alpha emitters which are not detected in SMUVS in the same field. We find that the emission line profile shown are 67% a single line, 3% a blue bump and 20% a red tail profile. The difference in profile distribution could be ascribed to the fainter Ly-alpha luminosities of the MUSE sources not detected in SMUVS and an intrinsically different mass distribution. Finally, we search for the presence of galaxy associations using the spectral redshifts. MUSE's integral coverage reveals that these associations are 20 times more likely than what is derived from all the other existing spectral data in COSMOS, which is biased by target pre-selection.
- ID:
- ivo://CDS.VizieR/J/A+A/621/A60
- Title:
- Bright nearby elliptical gal. Xshooter spectra
- Short Name:
- J/A+A/621/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new generation of spectral synthesis models has been developed in the recent years, but there is no matching -- in terms of quality and resolution -- set of template galaxy spectra for testing and refining the new models. Our main goal is to find and calibrate new near-infrared spectral indices along the Hubble sequence of galaxies which will be used to obtain additional constraints to the population analysis based on medium resolution integrated spectra of galaxies. Spectra of previously studied and well understood galaxies with relatively simple stellar populations (e.g., ellipticals or bulge dominated galaxies) are needed to provide a baseline data set for spectral synthesis models. X-Shooter spectra spanning the optical and infrared wavelength (350-2400nm) of bright nearby elliptical galaxies with resolving power R~4000-5400 were obtained. Heliocentric systemic velocity, velocity dispersion and Mg, Fe and H{beta} line-strength indices are presented. We present a library of very high quality spectra of galaxies covering a large range of age, metallicity and morphological type. Such as a dataset of spectra will be crucial to address important questions of the modern investigation concerning galaxy formation and evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/435/437
- Title:
- Brightness and diameters for extragalactic SNRs
- Short Name:
- J/A+A/435/437
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper examines relations between the radio surface brightness Sigma and the diameter D (also known as Sigma-D relations) for a sample of extragalactic supernova remnants (SNRs) as constructed from a combination of published data and data from our own surveys. Our sample of extragalactic SNRs is the largest ever devised for the purpose of analyzing Sigma-D relations.
