- ID:
- ivo://CDS.VizieR/J/other/ApSS/347.365
- Title:
- Paired galaxies and their supernovae
- Short Name:
- J/other/ApSS/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the influence of close neighbor galaxies on the properties of supernovae (SNe) and their host galaxies using 56 SNe located in pairs of galaxies with different levels of star formation (SF) and nuclear activity. The statistical study of SN hosts shows that there is no significant difference between morphologies of hosts in our sample and the larger general sample of SN hosts in the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8). The mean distance of type II SNe from nuclei of hosts is greater by about a factor of 2 than that of type Ibc SNe. The distributions and mean distances of SNe are consistent with previous results compiled with the larger sample. For the first time it is shown that SNe Ibc are located in pairs with significantly smaller difference of radial velocities between components than pairs containing SNe Ia and II. We consider this as a result of higher star formation rate (SFR) of these closer systems of galaxies. SN types are not correlated with the luminosity ratio of host and neighbor galaxies in pairs. The orientation of SNe with respect to the preferred direction toward neighbor galaxy is found to be isotropic and independent of kinematical properties of the galaxy pair.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/793/38
- Title:
- Palomar Transient Factory photometric observations
- Short Name:
- J/ApJ/793/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a Palomar Transient Factory (PTF) archival search for blue transients that lie in the magnitude range between "normal" core-collapse and superluminous supernovae (i.e., with -21<=M_R(peak)_<=-19). Of the six events found after excluding all interacting Type IIn and Ia-CSM supernovae, three (PTF09ge, 09axc, and 09djl) are coincident with the centers of their hosts, one (10iam) is offset from the center, and a precise offset cannot be determined for two (10nuj and 11glr). All the central events have similar rise times to the He-rich tidal disruption candidate PS1-10jh, and the event with the best-sampled light curve also has similar colors and power-law decay. Spectroscopically, PTF09ge is He-rich, while PTF09axc and 09djl display broad hydrogen features around peak magnitude. All three central events are in low star formation hosts, two of which are E+A galaxies. Our spectrum of the host of PS1-10jh displays similar properties. PTF10iam, the one offset event, is different photometrically and spectroscopically from the central events, and its host displays a higher star formation rate. Finding no obvious evidence for ongoing galactic nuclei activity or recent star formation, we conclude that the three central transients likely arise from the tidal disruption of a star by a supermassive black hole. We compare the spectra of these events to tidal disruption candidates from the literature and find that all of these objects can be unified on a continuous scale of spectral properties. The accumulated evidence of this expanded sample strongly supports a tidal disruption origin for this class of nuclear transients.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A100
- Title:
- Panchromatic SED of Herschel sources
- Short Name:
- J/A+A/551/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Combining far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, GOODS-S and COSMOS fields, it is possible to sample the 8-500 micron spectral energy distributions of galaxies with at least 7-10 bands. Extending to the UV, optical, and near- infrared, the number of bands increases up to 43. We reproduce the distribution of galaxies in a carefully selected 10 restframe color space, based on this rich data-set, using a superposition of multi-variate Gaussian modes. We use this model to classify galaxies and build median spectral energy distributions (SEDs) of each class, which are then fitted with a modified version of the MAGPHYS code that combines stellar light, emission from dust heated by stars and a possible warm dust contribution heated by an Active Galactic Nucleus (AGN). The color distribution of galaxies in each of the considered fields can be well described with the combination of 6-9 classes, spanning a large range of far- to near-IR luminosity ratios, as well as different strength of the AGN contribution to bolometric luminosities. The defined Gaussian grouping is used to identify rare or odd sources. The zoology of outliers includes Herschel-detected ellipticals, very blue z~1 Ly{alpha}-break galaxies, quiescent spirals, and torus-dominated AGN with star formation. Out of these groups and outliers, a new template library is assembled, consisting of 32 SEDs describing the intrinsic scatter in the restframe UV-to-submm colors of infrared galaxies. This library is tested against L(IR) estimates with and without Herschel data included, and compared to eight other popular methods often adopted in the literature. When implementing Herschel photometry, these approaches produce L(IR) values consistent with each other within a median absolute deviation of 10-20%, the scatter being dominated more by fine tuning of the codes, rather than by the choice of SED templates. Finally, the library is used to classify 24 micron detected sources in PEP GOODS fields on the basis of AGN content, L(60)/L(100) color and L(160)/L(1.6) luminosity ratio. AGN appear to be distributed in M*-SFR along with all other galaxies, regardless of the amount of infrared luminosity they are powering, with the tendency to lie on the high SFR side of the "main sequence". The incidence of warmer star-forming sources grows for objects with higher specific star formation rates, and they tend to populate the "off-sequence" region of the M*-SFR-z space.
- ID:
- ivo://CDS.VizieR/J/ApJ/776/80
- Title:
- PAndAS view of Andromeda satellites. I.
- Short Name:
- J/ApJ/776/80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a generic algorithm to search for dwarf galaxies in photometric catalogs and apply it to the Pan-Andromeda Archaeological Survey (PAndAS). The algorithm is developed in a Bayesian framework and, contrary to most dwarf galaxy search codes, makes use of both the spatial and color-magnitude information of sources in a probabilistic approach. Accounting for the significant contamination from the Milky Way foreground and from the structured stellar halo of the Andromeda galaxy, we recover all known dwarf galaxies in the PAndAS footprint with high significance, even for the least luminous ones. Some Andromeda globular clusters are also recovered and, in one case, discovered. We publish a list of the 143 most significant detections yielded by the algorithm. The combined properties of the 39 most significant isolated detections show hints that at least some of these trace genuine dwarf galaxies, too faint to be individually detected. Follow-up observations by the community are mandatory to establish which are real members of the Andromeda satellite system. The search technique presented here will be used in an upcoming contribution to determine the PAndAS completeness limits for dwarf galaxies. Although here tuned to the search of dwarf galaxies in the PAndAS data, the algorithm can easily be adapted to the search for any localized overdensity whose properties can be modeled reliably in the parameter space of any catalog.
- ID:
- ivo://CDS.VizieR/J/ApJ/833/167
- Title:
- PAndAS view of Andromeda satellites. II.
- Short Name:
- J/ApJ/833/167
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive analysis of the structural properties and luminosities of the 23 dwarf spheroidal galaxies that fall within the footprint of the Pan-Andromeda Archaeological Survey (PAndAS). These dwarf galaxies represent the large majority of Andromeda's known satellite dwarf galaxies and cover a wide range in luminosity (-11.6<~M_V_<~-5.8 or 10^4.2^<~L<~10^6.5^L_{sun}_) and surface brightness (25.1<~{mu}_0_<~29.3mag/arcsec^2^). We confirm most previous measurements, but we find And XIX to be significantly larger than before (r_h_=3065_-935_^+1065^pc, M_V_=-10.1_-0.4_^+0.8^) and cannot derive parameters for And XXVII as it is likely not a bound stellar system. We also significantly revise downward the luminosities of And XV and And XVI, which are now M_V_~-7.5 or L~10^5^L_{sun}_. Finally, we provide the first detailed analysis of Cas II/And XXX, a fairly faint system (M_V_=-8.0_-0.3_^+0.4^) of typical size (r_h_=270+/-50pc), located in close proximity to the two bright elliptical dwarf galaxies NGC 147 and NGC 185. Combined with the set of homogeneous distances published in an earlier contribution, our analysis dutifully tracks all relevant sources of uncertainty in the determination of the properties of the dwarf galaxies from the PAndAS photometric catalog. We further publish the posterior probability distribution functions of all the parameters we fit for in the form of MCMC chains available online; these inputs should be used in any analysis that aims to remain truthful to the data and properly account for covariance between parameters.
- ID:
- ivo://CDS.VizieR/J/AJ/161/71
- Title:
- Paramaters for 40 LITTLE THINGS galaxies
- Short Name:
- J/AJ/161/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The stellar, gaseous and young stellar disks in the LITTLE THINGS sample of nearby dwarf irregular galaxies are fitted with functions to search for correlations between the parameters. We find that the HI radial profiles are generally flatter in the center and fall faster in the outer regions than the V-band profiles, while young stars are more centrally concentrated, especially if the HI is more centrally flat. This pattern suggests that the HI is turning into molecules in the center, and the molecular clouds are forming stars and FUV. A model that assumes the molecular surface density is proportional to the total gas surface density to a power of 1.5 or 2, in analogy with the Kennicutt-Schmidt relation, reproduces the relationship between the ratio of the visible to the HI scale length and the HI Sersic index. The molecular fraction is estimated as a function of radius for each galaxy by converting the FUV to a molecular surface density using conventional calibrations. The average molecular fraction inside 3RD is 23%{+/-}17%. However, the break in the stellar surface brightness profile has no unified tracer related to star formation.
- ID:
- ivo://CDS.VizieR/J/ApJ/899/15
- Title:
- Parameters for the 58 {tau}HI(v) sightlines
- Short Name:
- J/ApJ/899/15
- Date:
- 14 Mar 2022 07:09:23
- Publisher:
- CDS
- Description:
- Resolving the phase structure of neutral hydrogen (HI) is crucial for understanding the life cycle of the interstellar medium (ISM). However, accurate measurements of HI temperature and density are limited by the availability of background continuum sources for measuring HI absorption. Here we test the use of deep learning for extracting HI properties over large areas without optical depth information. We train a 1D convolutional neural network using synthetic observations of 3D numerical simulations of the ISM to predict the fraction (f_CNM_) of cold neutral medium (CNM) and the correction to the optically thin HI column density for optical depth (R_H_I__) from 21cm emission alone. We restrict our analysis to high Galactic latitudes (|b|>30{deg}), where the complexity of spectral line profiles is minimized. We verify that the network accurately predicts f_CNM_ and R_H_I__ by comparing the results with direct constraints from 21cm absorption. By applying the network to the GALFA-HI survey, we generate large-area maps of f_CNM_ and R_H_I__. Although the overall contribution to the total HI column of CNM-rich structures is small (~5%), we find that these structures are ubiquitous. Our results are consistent with the picture that small-scale structures observed in 21cm emission aligned with the magnetic field are dominated by CNM. Finally, we demonstrate that the observed correlation between HI column density and dust reddening (E(B-V)) declines with increasing R_H_I__, indicating that future efforts to quantify foreground Galactic E(B-V) using HI, even at high latitudes, should increase fidelity by accounting for HI phase structure.
- ID:
- ivo://CDS.VizieR/J/A+A/486/755
- Title:
- Parameters of galaxies in 8 Abell clusters
- Short Name:
- J/A+A/486/755
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is a continuation of an ongoing study of the evolutionary processes affecting cluster galaxies. Both CCD R band and Halpha narrow-band imaging was used to determine photometric parameters (m_r_, r_24_, Halpha flux, and equivalent width) and derive star formation rates for 227 CGCG galaxies in 8 low-redshift clusters. The galaxy sample is a subset of CGCG galaxies in an objective prism survey (OPS) of cluster galaxies for Halpha emission. It is found that detection of emission-line galaxies in the OPS is 85%, 70%, and 50% complete at the mean surface brightness values of 1.25x10^-19^, 5.19x10^-20^, and 1.76x10^-20^W/m^2^/arcsec^2^, respectively, measured within the R band isophote of 24mag/arcsec^2^ for the galaxy. The CCD data, together with matched data from a recent Halpha galaxy survey of UGC galaxies within 3000km/s, will be used for a comparative study of R band and Halpha surface photometry between cluster and field spirals.
- ID:
- ivo://CDS.VizieR/J/ApJS/107/97
- Title:
- Parameters of 2447 southern spirals
- Short Name:
- J/ApJS/107/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I-band luminosities, rotational velocities, and redshifts of 1092 spiral galaxies have been measured by CCD photometry and Halpha spectroscopy using the 1m and 2.3m telescopes at Siding Spring Observatory, respectively. The results are tabulated. Luminosity profiles and Halpha rotation curves are given for the galaxies. When these results are combined with similar data for 1355 spiral galaxies published previously (Mathewson, Ford, & Buchhorn, hereafter Paper I, 1992ApJS...81..413M), it provides a large, uniform, and unique data set with which to measure, via the Tully-Fisher relation, the peculiar velocities of galaxies in the local universe to a distance of 11,000km/s (Mathewson & Ford, in Proc. Heron Island Workshop on Peculiar Velocities in the Universe). Taking advantage of the opportunity for publishing this data in machine-readable form, in the CD-ROM, we have also published similar data for the 1355 galaxies in Paper I.
- ID:
- ivo://CDS.VizieR/J/MNRAS/425/2741
- Title:
- Parameters of Spiral galaxies from SDSS 7
- Short Name:
- J/MNRAS/425/2741
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled a sample of 3041 spiral galaxies with multiband gri imaging from the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7; Abazajian et al., 2009ApJS..182..543A) and available galaxy rotational velocities, V, derived from HI linewidths. We compare the data products provided through the SDSS imaging pipeline with our own photometry of the SDSS images, and use the velocities, V, as an independent metric to determine ideal galaxy sizes (R) and luminosities (L). Our radial and luminosity parameters improve upon the SDSS DR7 Petrosian radii and luminosities through the use of isophotal fits to the galaxy images. This improvement is gauged via VL (Vmag-Luminosity) and RV relations whose respective scatters are reduced by ~8 and ~30% with our parameters compared to similar relations built with SDSS parameters.
