- ID:
- ivo://CDS.VizieR/J/ApJ/722/L120
- Title:
- Central surface brightness of 30000 SDSS galaxies
- Short Name:
- J/ApJ/722/L120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Disc central surface brightness for 30000 galaxies from the Sloan Digitized Sky Survey (SDSS) Data Release 7, in the r-band. Virtual Observatory methods and tools were used to define, retrieve and analyze the images for this unprecedentedly large sample classified as spiral galaxies in the LEDA catalogue. These parameters are also available for all other SDSS bands (u,g,i,z), and they can be retrieved from the Author.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/827/L19
- Title:
- Central surface densities in SPARC disk galaxies
- Short Name:
- J/ApJ/827/L19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Spitzer Photometry and Accurate Rotation Curves (SPARC) database to study the relation between the central surface density of stars {Sigma}_*_(0) and dynamical mass {Sigma}_dyn_(0) in 135 disk galaxies (S0 to dIrr). We find that {Sigma}_dyn_(0) correlates tightly with {Sigma}_*_(0) over 4dex. This central density relation can be described by a double power law. High surface brightness galaxies are consistent with a 1:1 relation, suggesting that they are self-gravitating and baryon dominated in the inner parts. Low surface brightness (LSB) galaxies systematically deviate from the 1:1 line, indicating that the dark matter contribution progressively increases but remains tightly coupled to the stellar one. The observed scatter is small (~0.2dex) and largely driven by observational uncertainties. The residuals show no correlations with other galaxy properties like stellar mass, size, or gas fraction.
- ID:
- ivo://CDS.VizieR/J/ApJ/464/79
- Title:
- CFRS XI: High-redshift field galaxies morphology
- Short Name:
- J/ApJ/464/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 143 galaxies with secure redshifts (Z_median_=0.62) from the 1415+52 field of the Canada-France Redshift Survey have been imaged with median seeing of 0.67" (FWHM). Structural parameters have been derived by fitting multicomponent models and the results confirm two phenomena seen in a smaller sample of galaxies imaged with the Hubble Space Telescope. First, 11+/-3% of the galaxies lie off the normal locus of color versus bulge fraction B/T. This class of objects ("blue nucleated galaxies," or BNGs) was identified using HST observations (Schade et al. 1995ApJ...451L...1S, hereafter CFRS IX), and it was shown that they are associated with peculiar/asymmetric structure and merger/interactions. The observed frequency of BNGs in this sample is 14+/-4% 0.5<z<1.2 and 6^+6^_-3_% at 0.2<z<0.5, but the true frequency is likely to be a factor ~2 higher after corrections are made for the effect of asymmetric/peculiar structures. Galaxy disks at 0.5<z<1.1 are found to have a mean rest-frame, inclination-corrected central surface brightness of {mu}_AB_(B)=19.8+/-0.1mag/arcsec^2^, ~1.6mag brighter than the Freeman (1970ApJ...160..811F) value. At low redshift (0.2<z<0.5) the mean surface brightness [{mu}_AB_(B)=21.3+/-0.25] is consistent with the Freeman value. These results are consistent with the HST observations. With larger numbers of galaxies and therefore more statistical weight they demonstrate the capabilities, and limits, of ground-based work in the study of galaxy morphology at high redshift.
- ID:
- ivo://CDS.VizieR/J/ApJ/845/87
- Title:
- CGS. V. Statistical study of bars and buckled bars
- Short Name:
- J/ApJ/845/87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Simulations have shown that bars are subject to a vertical buckling instability that transforms thin bars into boxy or peanut-shaped structures, but the physical conditions necessary for buckling to occur are not fully understood. We use the large sample of local disk galaxies in the Carnegie-Irvine Galaxy Survey to examine the incidence of bars and buckled bars across the Hubble sequence. Depending on the disk inclination angle (i), a buckled bar reveals itself as either a boxy/peanut-shaped bulge (at high i) or as a barlens structure (at low i). We visually identify bars, boxy/peanut-shaped bulges, and barlenses, and examine the dependence of bar and buckled bar fractions on host galaxy properties, including Hubble type, stellar mass, color, and gas mass fraction. We find that the barred and unbarred disks show similar distributions in these physical parameters. The bar fraction is higher (70%-80%) in late-type disks with low stellar mass (M*<10^10.5^M_{sun}_) and high gas mass ratio. In contrast, the buckled bar fraction increases to 80% toward massive and early-type disks (M*>10^10.5^M_{sun}_), and decreases with higher gas mass ratio. These results suggest that bars are more difficult to grow in massive disks that are dynamically hotter than low-mass disks. However, once a bar forms, it can easily buckle in the massive disks, where a deeper potential can sustain the vertical resonant orbits. We also find a probable buckling bar candidate (ESO506-G004) that could provide further clues to understand the timescale of the buckling process.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/952
- Title:
- Chandra Deep Field-South ATLAS 5.5GHz DR2
- Short Name:
- J/MNRAS/454/952
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new image of the 5.5GHz radio emission from the extended Chandra Deep Field South. Deep radio observations at 5.5GHz were obtained in 2010 and presented in the first data release. A further 76h of integration has since been obtained, nearly doubling the integration time. This paper presents a new analysis of all the data. The new image reaches 8.6{mu}Jy rms, an improvement of about 40% in sensitivity. We present a new catalogue of 5.5GHz sources, identifying 212 source components, roughly 50% more than were detected in the first data release. Source counts derived from this sample are consistent with those reported in the literature for S_5.5GHz_>0.1mJy but significantly lower than published values in the lowest flux density bins (S_5.5GHz_<0.1mJy), where we have more detected sources and improved statistical reliability. The 5.5GHz radio sources were matched to 1.4GHz sources in the literature and we find a mean spectral index of -0.35+/-0.10 for S_5.5GHz_>0.5mJy, consistent with the flattening of the spectral index observed in 5GHz sub-mJy samples. The median spectral index of the whole sample is {alpha}_med_=-0.58, indicating that these observations may be starting to probe the star-forming population. However, even at the faintest levels (0.05<S_5.5GHz_<0.1mJy), 39% of the 5.5GHz sources have flat or inverted radio spectra. Four flux density measurements from our data, across the full 4.5-6.5GHz bandwidth, are combined with those from literature and we find 10% of sources (S_5.5GHz_>~0.1mJy) show significant curvature in their radio spectral energy distribution spanning 1.4-9GHz.
- ID:
- ivo://CDS.VizieR/J/AZh/91/679
- Title:
- Chandra X-Ray galaxy clusters at z <1.4
- Short Name:
- J/AZh/91/679
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A reconstruction of the total mass (the fraction of dark matter, intercluster gas, and the brightest galaxy of the cluster) of 128 X-ray galaxy clusters at redshifts 0.01-1.4 based on Chandra observations is presented. The total mass M200 and the baryonic mass Mb have been measured for all the sample objects, as well as the concentration parameter c200, which characterizes the size of the dark matter halo. The existence of a tight correlation between c200 and M200 is confirmed, c{prop.to}M^a^_vir_/(1+z)b with a=-0.56+/-0.15 and b=0.80+/-0.25 (95% confidence level), in good agreement with the predictions of numerical simulations and previous observations. Fitting the inner dark-matter density slope {alpha} with a generalized NFW model yields {alpha}=1.10+/-0.48 at the 2{sigma} confidence level, combining the results for the entire sample, for which the model gives a good description of the data. There is also a tight correlation between the inner slope of the dark-matter density profile {alpha} and the baryonic mass contentMb for massive galaxy clusters, namely, {alpha} decreases with increasing baryonic mass content. A simple power-law model is used to fit the {alpha}-M_b_ distributions, yielding the break point for the inner slope of the dark-matter density profile b=1.72+/-0.37 (68% confidence level).
- ID:
- ivo://CDS.VizieR/J/ApJS/146/353
- Title:
- Circumnuclear dust in galaxies
- Short Name:
- J/ApJS/146/353
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The detailed morphology of the interstellar medium (ISM) in the central kiloparsec of galaxies is controlled by pressure and gravitation. The combination of these forces shapes both circumnuclear star formation and the growth of the central, supermassive black hole. We present visible and near-infrared Hubble Space Telescope images and color maps of 123 nearby galaxies that show the distribution of the cold ISM, as traced by dust, with excellent spatial resolution. These observations reveal that nuclear dust spirals are found in the majority of active and inactive galaxies and they possess a wide range in coherence, symmetry, and pitch angle. We have used this large sample to develop a classification system for circumnuclear dust structures.
- ID:
- ivo://CDS.VizieR/J/ApJ/616/707
- Title:
- Circumnuclear structure of NICMOS galaxies
- Short Name:
- J/ApJ/616/707
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Why are the nuclei of some galaxies more active than others? If most galaxies harbor a central massive black hole, the main difference is probably in how well it is fueled by its surroundings. We investigate the hypothesis that such a difference can be seen in the detailed circumnuclear morphologies of galaxies using several quantitatively defined features, including bars, isophotal twists, boxy and disky isophotes, and strong nonaxisymmetric features in unsharp-masked images. These diagnostics are applied to 250 high-resolution images of galaxy centers obtained in the near-infrared with NICMOS on the Hubble Space Telescope. To guard against the influence of possible biases and selection effects, we have carefully matched samples of Seyfert 1, Seyfert 2, LINER, starburst, and normal galaxies in their basic properties, taking particular care to ensure that each was observed with a similar average scale (10-15pc/pixel).
- ID:
- ivo://CDS.VizieR/J/A+A/580/A131
- Title:
- Circumstellar-interacting supernovae
- Short Name:
- J/A+A/580/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Some circumstellar-interacting (CSI) supernovae (SNe) are produced by the explosions of massive stars that have lost mass shortly before the SN explosion. There is evidence that the precursors of some SNe IIn were luminous blue variable (LBV) stars. For a small number of CSI SNe, outbursts have been observed before the SN explosion. Eruptive events of massive stars are named SN impostors (SN IMs) and whether they herald a forthcoming SN or not is still unclear. The large variety of observational properties of CSI SNe suggests the existence of other progenitors, such as red supergiant (RSG) stars with superwinds. Furthermore, the role of metallicity in the mass loss of CSI SN progenitors is still largely unexplored. Our goal is to gain insight into the nature of the progenitor stars of CSI SNe by studying their environments, in particular the metallicity at their locations. We obtain metallicity measurements at the location of 60 transients (including SNe IIn, SNe Ibn, and SN IMs) via emission-line diagnostic on optical spectra obtained at the Nordic Optical Telescope and through public archives. Metallicity values from the literature complement our sample. We compare the metallicity distributions among the different CSI SN subtypes, and to those of other core-collapse SN types. We also search for possible correlations between metallicity and CSI SN observational properties. We find that SN IMs tend to occur in environments with lower metallicity than those of SNe IIn. Among SNe IIn, SN IIn-L(1998S-like) SNe show higher metallicities, similar to those of SNe IIL/P, whereas long-lasting SNe IIn (1988Z-like) show lower metallicities, similar to those of SN IMs. The metallicity distribution of SNe IIn can be reproduced by combining the metallicity distributions of SN IMs (which may be produced by major outbursts of massive stars like LBVs) and SNe IIP (produced by RSGs). The same applies to the distributions of the normalized cumulative rank (NCR) values, which quantifies the SN association to HII regions. For SNe IIn, we find larger mass-loss rates and higher CSM velocities at higher metallicities. The luminosity increment in the optical bands during SN IM outbursts tend to be larger at higher metallicity, whereas the SN IM quiescent optical luminosities tend to be lower. The difference in metallicity between SNe IIn and SN IMs indicates that LBVs are only one of the progenitor channels for SNe IIn, with 1988Z-like and 1998S-like SNe possibly arising from LBVs and RSGs, respectively. Finally, even though line-driven winds likely do not primarily drive the late mass-loss of CSI SN progenitors, metallicity has some impact on the observational properties of these transients.
- ID:
- ivo://CDS.VizieR/J/AJ/132/1275
- Title:
- CIRS (Cluster Infall Regions in the SDSS). I.
- Short Name:
- J/AJ/132/1275
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Fourth Data Release of the Sloan Digital Sky Survey (SDSS) to test the ubiquity of infall patterns around galaxy clusters and measure cluster mass profiles to large radii. The Cluster and Infall Region Nearby Survey (CAIRNS) found infall patterns in nine clusters, but the cluster sample was incomplete. Here we match X-ray cluster catalogs with SDSS, search for infall patterns, and compute mass profiles for a complete sample of X-ray-selected clusters. Very clean infall patterns are apparent in most of the clusters, with the fraction decreasing with increasing redshift due to shallower sampling. All 72 clusters in a well-defined sample limited by redshift (ensuring good sampling) and X-ray flux (excluding superpositions) show infall patterns sufficient to apply the caustic technique. This sample is by far the largest sample of cluster mass profiles extending to large radii to date. Similar to CAIRNS, cluster infall patterns are better defined in observations than in simulations. Further work is needed to determine the source of this difference. We use the infall patterns to compute mass profiles for 72 clusters and compare them to model profiles. Cluster scaling relations using caustic masses agree well with those using X-ray or virial mass estimates, confirming the reliability of the caustic technique. We confirm the conclusion of CAIRNS that cluster infall regions are well fitted by Navarro-Frenk-White (NFW) and Hernquist profiles and poorly fitted by singular isothermal spheres. This much larger sample enables new comparisons of cluster properties with those in simulations. The shapes (specifically NFW concentrations) of the mass profiles agree well with the predictions of simulations. The mass in the infall region is typically comparable to or larger than that in the virial region. Specifically, the mass inside the turnaround radius is on average 2.19+/-0.18 times that within the virial radius. This ratio agrees well with recent predictions from simulations of the final masses of dark matter halos.
