- ID:
- ivo://CDS.VizieR/J/A+A/627/A108
- Title:
- Properties of COMP2CAT sources
- Short Name:
- J/A+A/627/A108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of compact double radio galaxies (hereafter COMP2CAT) listing 43 edge-brightened radio sources whose projected linear size does not exceed 60 kpc, the typical size of their host galaxies. This is the fifth in a series of radio source catalogs recently created, namely: FRICAT, FRIICAT, FR0CAT, and WATCAT, each of which focuses on a different class of radio galaxies. The main aim of our analysis is to attain a better understanding of sources with intermediate morphologies between FR IIs and FR 0s. COMP2CAT sources were selected from an existing catalog of radio sources based on NVSS, FIRST and SDSS observations because they have i) edge-brightened morphologies typical of FR IIs, ii) redshifts z<0.15, and iii) projected linear sizes smaller than 60kpc. With radio luminosities at 1.4GHz 10^38^<L_1.4_<10^41^erg/s, COMP2CAT sources appear as the low radio luminosity tail of FR IIs. However, their host galaxies are indistinguishable from those of large-scale radio sources: they are luminous (-21>M_r_>-24), red, early-type galaxies with black hole masses in the range 10^7.5^<M_BH_<10^9.5^M_{sun}_. Moreover, all but one of the COMP2CAT sources are optically classifiable as low-excitation radio galaxies, in agreement with being the low radio luminosity tail of FR Is and FR IIs. This catalog of compact double sources, which is ~47% complete at z<0.15, can potentially be used to clarify the role of compact double sources in the general evolutionary scheme of radio galaxies.
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- ID:
- ivo://CDS.VizieR/J/AJ/143/133
- Title:
- Properties of dwarf galaxies from the ALFALFA survey
- Short Name:
- J/AJ/143/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the global properties of the stellar and HI components of 229 low HI mass dwarf galaxies extracted from the ALFALFA survey ({alpha}.40; Haynes et al., 2011, Cat. J/AJ/142/170), including a complete sample of 176 galaxies with HI masses<10^7.7^M_{sun}_and HI line widths<80km/s. Sloan Digital Sky Survey (SDSS; Cat . II/294 superseded by Cat. V/139) data are combined with photometric properties derived from Galaxy Evolution Explorer (GALEX; GR5, Cat. II/312) to derive stellar masses (M_*_) and star formation rates (SFRs) by fitting their UV-optical spectral energy distributions (SEDs). In optical images, many of the ALFALFA dwarfs are faint and of low surface brightness; only 56% of those within the SDSS footprint have a counterpart in the SDSS spectroscopic survey. A large fraction of the dwarfs have high specific star formation rates (SSFRs), and estimates of their SFRs and M_*_ obtained by SED fitting are systematically smaller than ones derived via standard formulae assuming a constant SFR. The increased dispersion of the SSFR distribution at M_*_<~10^8^M_{sun}_ is driven by a set of dwarf galaxies that have low gas fractions and SSFRs; some of these are dE/dSphs in the Virgo Cluster. The imposition of an upper HI mass limit yields the selection of a sample with lower gas fractions for their M_*_ than found for the overall ALFALFA population. Many of the ALFALFA dwarfs, particularly the Virgo members, have HI depletion timescales shorter than a Hubble time. An examination of the dwarf galaxies within the full ALFALFA population in the context of global star formation (SF) laws is consistent with the general assumptions that gas-rich galaxies have lower SF efficiencies than do optically selected populations and that HI disks are more extended than stellar ones.
- ID:
- ivo://CDS.VizieR/J/AJ/144/4
- Title:
- Properties of dwarf galaxies in the Local Group
- Short Name:
- J/AJ/144/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Positional, structural, and dynamical parameters for all dwarf galaxies in and around the Local Group are presented, and various aspects of our observational understanding of this volume-limited sample are discussed. Over 100 nearby galaxies that have distance estimates reliably placing them within 3Mpc of the Sun are identified. This distance threshold samples dwarfs in a large range of environments, from the satellite systems of the MW and M31, to the quasi-isolated dwarfs in the outer regions of the Local Group, to the numerous isolated galaxies that are found in its surroundings. It extends to, but does not include, the galaxies associated with the next nearest groups, such as Maffei, Sculptor, and IC 342. Our basic knowledge of this important galactic subset and their resolved stellar populations will continue to improve dramatically over the coming years with existing and future observational capabilities, and they will continue to provide the most detailed information available on numerous aspects of dwarf galaxy formation and evolution. Basic observational parameters, such as distances, velocities, magnitudes, mean metallicities, as well as structural and dynamical characteristics, are collated, homogenized (as far as possible), and presented in tables that will be continually updated to provide a convenient and current online resource. As well as discussing the provenance of the tabulated values and possible uncertainties affecting their usage, the membership and spatial extent of the MW sub-group, M31 sub-group, and the Local Group are explored. The morphological diversity of the entire sample and notable sub-groups is discussed, and timescales are derived for the Local Group members in the context of their orbital/interaction histories. The scaling relations and mean stellar metallicity trends defined by the dwarfs are presented, and the origin of a possible "floor" in central surface brightness (and, more speculatively, stellar mean metallicity) at faint magnitudes is considered.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/79
- Title:
- Properties of emission-line galaxies
- Short Name:
- J/ApJ/817/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare the physical and morphological properties of z~2 Ly{alpha} emitting galaxies (LAEs) identified in the HETDEX Pilot Survey and narrow band studies with those of z~2 optical emission line selected galaxies (oELGs) identified via HST WFC3 infrared grism spectroscopy. Both sets of galaxies extend over the same range in stellar mass (7.5<logM/M_{sun}_<10.5), size (0.5<R<3.0kpc), and star formation rate (~1<SFR<100M_{sun}_/yr). Remarkably, a comparison of the most commonly used physical and morphological parameters - stellar mass, half-light radius, UV slope, SFR, ellipticity, nearest neighbor distance, star formation surface density, specific SFR, [OIII] luminosity, and [OIII] equivalent width - reveals no statistically significant differences between the populations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/4346
- Title:
- Properties of 1329 extended radio galaxies
- Short Name:
- J/MNRAS/466/4346
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Powerful radio galaxies exist as either compact or extended sources, with the extended sources traditionally classified by their radio morphologies as Fanaroff-Riley (FR) type I and II sources. FRI/FRII and compact radio galaxies have also been classified by their optical spectra into two different types: high excitation (HERG; quasar-mode) and low excitation (LERG; jet-mode). We present a catalogue of visual morphologies for a complete sample of >1000 1.4-GHz-selected extended radio sources from the Sloan Digital Sky Survey. We study the environment and host galaxy properties of FRI/FRII and compact sources, classified into HERG/LERG types, in order to separate and distinguish the factors that drive the radio morphological variations from those responsible for the spectral properties. Comparing FRI LERGs with FRII LERGs at fixed stellar mass and radio luminosity, we show that FRIs typically reside in richer environments and are hosted by smaller galaxies with higher mass surface density; this is consistent with extrinsic effects of jet disruption driving the Fanaroff-Riley (FR) dichotomy. Using matched samples of HERGs and LERGs, we show that HERG host galaxies are more frequently star forming, with more evidence for disc-like structure than LERGs, in accordance with currently favoured models of fundamentally different fuelling mechanisms. Comparing FRI/FRII LERGs with compact LERGs, we find the primary difference is that compact objects typically harbour less massive black holes. This suggests that lower mass black holes may be less efficient at launching stable radio jets, or do so for shorter times. Finally, we investigate rarer sub-classes: wide-angle-tailed, head-tail, FR-hybrid and double-double sources.
- ID:
- ivo://CDS.VizieR/J/AJ/158/229
- Title:
- Properties of FUV bright SFRs in IC 2574
- Short Name:
- J/AJ/158/229
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Star-forming dwarf galaxies in the local volume are diverse and ideal test beds to understand the details of star formation in a variety of environments. Here we present a deep far-UV (FUV) imaging study of the nearby dwarf irregular galaxy IC 2574 using the Ultraviolet Imaging Telescope. We identified 419 FUV-bright regions with radii between 15 and 285 pc in the galaxy and found that 28.6% of them are located in H I shells, 12.6% inside holes, and 60.1% away from the holes. The H I column density is found to be more than 10^21^ cm^-2^ for 82.3% of the identified regions. Thirty of the 48 H I holes show triggered star formation in their shells, while 16 holes do not show any related FUV emission. Cross-matching with H{alpha} emission, we found that 23 holes have both FUV and H{alpha} emission in their shells, signifying a very recent trigger. Therefore, star formation in the galaxy has been partly triggered due to the expanding H I holes, whereas in the majority of the sites, it is driven by other mechanisms. Irrespective of the location, larger star-forming complexes were found to have multiple substructures. We report two resolved components for the remnant cluster of the supergiant shell and estimate their masses. The star formation rate of IC 2574 is found to be 0.57 M_{sun}_/yr, which is slightly higher compared to the average value of other nearby dwarf irregular galaxies.
- ID:
- ivo://CDS.VizieR/J/PASP/117/227
- Title:
- Properties of 101 galaxies from the NFGS
- Short Name:
- J/PASP/117/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use 101 galaxies selected from the Nearby Field Galaxy Survey to investigate the effect of aperture size on the star formation rate, metallicity, and reddening determinations for galaxies. Our sample includes galaxies of all Hubble types except ellipticals with global star formation rates (SFRs) ranging from 0.01 to 100M_{sun}_/yr, metallicities in the range 7.9<~log(O/H)+12<~9.0, and reddening of 0<~A(V)<~3.3. We compare the SFR, metallicity, and reddening derived from nuclear spectra to those derived from integrated spectra.
- ID:
- ivo://CDS.VizieR/J/ApJ/899/159
- Title:
- Properties of 10 galaxies with Chandra
- Short Name:
- J/ApJ/899/159
- Date:
- 11 Mar 2022 14:27:52
- Publisher:
- CDS
- Description:
- We present an archival analysis of Chandra X-ray observations for 12 nearby early-type galaxies hosting radio sources with radio power >1023W/Hz at 1.4GHz, similar to the radio power of the radio source in NGC4261. Previously, in a similar analysis of eight nearby X-ray and optically bright elliptical galaxies, Werner et al. found that NGC4261 exhibited unusually low central gas entropy compared to the full sample. In the central 0.3kpc of NGC4261, the ratio of cooling time to freefall time (tcool/tff) is less than 10, indicating that cold clouds may be precipitating out of the hot ambient medium and providing fuel for accretion in the central region. NGC4261 also hosts the most powerful radio source in the original sample. Because NGC4261 may represent an important phase during which powerful feedback from a central active galactic nucleus (AGN) is fueled by multiphase condensation in the central kiloparsec, we searched the Chandra archive for analogs to NGC4261. We present entropy profiles of those galaxies, as well as profiles of tcool/tff. We find that one of them, IC4296, exhibits properties similar to NGC4261, including the presence of only single-phase gas outside of r~2kpc and a similar central velocity dispersion. We compare the properties of NGC4261 and IC4296 to hydrodynamic simulations of AGN feedback fueled by precipitation. Over the course of those simulations, the single-phase galaxy has an entropy gradient that remains similar to the entropy profiles inferred from our observations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/4238
- Title:
- Properties of IR-bright AGNs
- Short Name:
- J/MNRAS/478/4238
- Date:
- 10 Dec 2021 00:55:32
- Publisher:
- CDS
- Description:
- We report the relationship between the luminosities of active galactic nuclei (AGNs) and the rates of star formation (SF) for a sample of 323 far-infrared (FIR)-detected AGNs. This sample has a redshift range of 0.2<z<2.5, and spans three orders of magnitude in luminosity, L_X_~10^42-45^erg/s. We find that in AGN hosts, the total infrared (IR) luminosity (8-1000um) has a significant AGN contribution (average ~20 per cent), and we suggest using the FIR luminosity (30-1000um) as a more reliable star formation rate (SFR) estimator. We conclude that monochromatic luminosities at 60 and 100um are also good SFR indicators with negligible AGN contributions, being less sensitive than integrated IR luminosities to the shape of the AGN spectral energy distribution (SED), which is uncertain at {lambda}>100um. Significant bivariate L_X_-L_IR_ correlations are found, which remain significant in the combined sample when using residual partial correlation analysis to account for the inherent redshift dependence. No redshift or mass dependence is found for the ratio between SFR and black hole accretion rate (BHAR), which has a mean and scatter of log(SFR/BHAR)=3.1+/-0.5, agreeing with the local mass ratio between supermassive black hole and host galaxies. The large scatter in this ratio and the strong AGN-SF correlation found in these IR-bright AGNs are consistent with the scenario of an AGN-SF dependence on a common gas supply, regardless of the evolutionary model.
- ID:
- ivo://CDS.VizieR/J/A+A/420/873
- Title:
- Properties of isolated disk galaxies
- Short Name:
- J/A+A/420/873
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new sample of northern isolated galaxies, which are defined by the physical criterion that they were not affected by other galaxies in their evolution during the last few Gyr. To find them we used the logarithmic ratio, f, between inner and tidal forces acting upon the candidate galaxy by a possible perturber.