- ID:
- ivo://CDS.VizieR/J/MNRAS/371/963
- Title:
- Deep VLA survey in Lockman Hole, HDFN, ELAIS N2
- Short Name:
- J/MNRAS/371/963
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present catalogues of faint 1.4-GHz radio sources from extremely deep Very Large Array pointings in the Lockman Hole, the Hubble Deep Field-North (HDF-N) and the European Large Area ISO Survey (ELAIS) N2 field. Our analysis of the HDF-N data has produced maps that are significantly deeper than those previously published, and we have used these to search for counterparts to submillimetre sources. For each of the fields, we have derived normalized differential source counts and in the case of the HDF-N find no evidence for the previously reported underdensity of sources; our counts are entirely consistent with those found for the majority of other fields. The catalogues are available as an online supplement to this paper and the maps are also available for download.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/438/507
- Title:
- Degree of lopsidedness for galaxies
- Short Name:
- J/A+A/438/507
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We quantify the degree of lopsidedness for a sample of 149 galaxies observed in the near-infrared from the Ohio State University Bright Galaxy Survey (OSUBGS, Eskridge et al. 2002, Cat. <J/ApJS/143/73>) sample, and try to explain the physical origin of the observed disk lopsidedness. We confirm previous studies, but for a larger sample, that a large fraction of galaxies have significant lopsidedness in their stellar disks, measured as the Fourier amplitude of the m=1 component normalised to the average or m=0 component in the surface density. Late-type galaxies are found to be more lopsided, while the presence of m=2 spiral arms and bars is correlated with disk lopsidedness. We also show that the m=1 amplitude is uncorrelated with the presence of companions. Numerical simulations were carried out to study the generation of m=1 via different processes: galaxy tidal encounters, galaxy mergers, and external gas accretion with subsequent star formation. These simulations show that galaxy interactions and mergers can trigger strong lopsidedness, but do not explain several independent statistical properties of observed galaxies. To explain all the observational results, it is required that a large fraction of lopsidedness results from cosmological accretion of gas on galactic disks, which can create strongly lopsided disks when this accretion is asymmetrical enough.
- ID:
- ivo://CDS.VizieR/J/A+A/363/62
- Title:
- DENIS galaxies around 16h15m -30deg
- Short Name:
- J/A+A/363/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From a visual inspection of J and K images obtained within the Deep Near Infrared Survey (DENIS) we detected 37 noteworthy galaxies near the galactic plane (|b|<15{deg}). Most of these galaxies are yet uncatalogued. They have either a large dimension (more than 1arcmin in J-band) or a position very close to the galactic plane (|b|<3{deg}). Some of these galaxies are simply not visible on the Digitized Sky Survey. Among them 15 galaxies are suspected to be spirals and could be detected from HI observations. Several large galaxies near the assumed position of the Great Attractor suggests that a concentration of galaxies may be present around the equatorial position: {alpha}_2000_=16h15m, {delta}_2000_=-30{deg}. An inspection of this field from the Digitized Sky Survey and from available 2MASS data confirms the presence of extragalactic structures.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/342
- Title:
- Dense cores in Taurus L1495 cloud
- Short Name:
- J/MNRAS/459/342
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of dense cores in a ~4{deg}x2{deg} field of the Taurus star-forming region, inclusive of the L1495 cloud, derived from Herschel SPIRE and PACS observations in the 70{mu}m, 160{mu}m, 250{mu}m, 350{mu}m, and 500{mu}m continuum bands. Estimates of mean dust temperature and total mass are derived using modified blackbody fits to the spectral energy distributions. We detect 525 starless cores of which ~10-20 per cent are gravitationally bound and therefore presumably prestellar. Our census of unbound objects is ~85 per cent complete for M>0.015M_{sun}_ in low-density regions (A_V_<~5mag), while the bound (prestellar) subset is ~85 per cent complete for M>0.1M_{sun}_ overall. The prestellar core mass function (CMF) is consistent with lognormal form, resembling the stellar system initial mass function, as has been reported previously. All of the inferred prestellar cores lie on filamentary structures whose column densities exceed the expected threshold for filamentary collapse, in agreement with previous reports. Unlike the prestellar CMF, the unbound starless CMF is not lognormal, but instead is consistent with a power-law form below 0.3M_{sun}_ and shows no evidence for a low-mass turnover. It resembles previously reported mass distributions for CO clumps at low masses (M<~0.3M_{sun}_). The volume density PDF, however, is accurately lognormal except at high densities. It is consistent with the effects of self-gravity on magnetized supersonic turbulence. The only significant deviation from lognormality is a high-density tail which can be attributed unambiguously to prestellar cores.
- ID:
- ivo://CDS.VizieR/J/ApJ/665/1194
- Title:
- Dense cores in the Orion A cloud survey
- Short Name:
- J/ApJ/665/1194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out an H^13^CO^+^ (J=1-0) core survey in a large area of 1.5degx0.5deg, covering the whole region of the Orion A molecular cloud, using the Nobeyama 45m radio telescope with the 25 Beam Array Receiver System (BEARS). This survey is unique in that a large area (~48pc^2^) of the cloud was covered with a high spatial resolution of 21" (0.05pc) and with a deep integration (1sigma~0.1K in T*_A_), resulting in a core mass detection of 1.6M_{sun}_. The morphology of the H^13^CO^+^ (J=1-0) emission is very similar to that of the 850um continuum emission. We identified 236 dense cores from our data with the clumpfind algorithm. The cores are close to virial equilibrium, independent of whether they are thermal or turbulent.
- ID:
- ivo://CDS.VizieR/J/A+A/421/595
- Title:
- Deprojecting spiral galaxies method
- Short Name:
- J/A+A/421/595
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use two new methods developed recently (Barbera et al., 2004, Cat. <J/A+A/415/849>), as well as information obtained from the literature, to calculate the orientation parameters of the spiral galaxies in the Ohio State University Bright Spiral Galaxy Survey (OSUBSGS). We compare the results of these methods with data from the literature, and find in general good agreement. We provide a homogeneous set of mean orientation parameters which can be used to approximately deproject the disks of the galaxies and facilitate a number of statistical studies of galaxy properties.
- ID:
- ivo://CDS.VizieR/J/A+A/415/849
- Title:
- Deprojection of spiral galaxies
- Short Name:
- J/A+A/415/849
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present two methods that can be used to deproject spirals, based on Fourier analysis of their images, and discuss their potential and restrictions. Our methods perform particularly well for galaxies more inclined than 50 degrees or for non-barred galaxies more inclined than 35 degrees. They are fast and straightforward to use, and thus ideal for large samples of galaxies. Moreover, they are very robust for low resolutions and thus are appropriate for samples of cosmological interest. The relevant software is available from us upon request. We use these methods to determine the values of the position and inclination angles for a sample of 81 spiral galaxies contained in the Frei et al. (1996AJ....111..174F) sample. We compare our results with the values found in the literature, based on other methods. We find statistically very good agreement.
- ID:
- ivo://CDS.VizieR/J/ApJS/186/427
- Title:
- Detailed morphology of SDSS galaxies
- Short Name:
- J/ApJS/186/427
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of detailed visual classifications for 14034 galaxies in the Sloan Digital Sky Survey (SDSS) Data Release 4 (DR4, Cat. <II/267>). Our sample includes nearly all spectroscopically targeted galaxies in the redshift range 0.01<z<0.1 down to an apparent extinction-corrected limit of g<16mag. In addition to T-Types, we record the existence of bars, rings, lenses, tails, warps, dust lanes, arm flocculence, and multiplicity. This sample defines a comprehensive local galaxy sample which we will use in future papers to study low-redshift morphology. It will also prove useful for calibrating automated galaxy classification algorithms. In this paper, we describe the classification methodology used, detail the systematics and biases of our sample, and summarize the overall statistical properties of the sample, noting the most obvious trends that are relevant for general comparisons of our catalog with previously published work.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1559
- Title:
- Diameters of Galactic open star clusters
- Short Name:
- J/AJ/131/1559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present paper presents a tabulation of data on all 600 Galactic open clusters for which it is currently possible to calculate linear diameters. As expected, the youngest "clusters", with ages <15Myr, contain a significant (>=20%) admixture of associations. Among intermediate-age clusters, with ages in the range 15Myr to 1.5Gyr, the median cluster diameter is found to increase with age. Small, compact clusters are rare among objects with ages >1.5Gyr. Open clusters with ages >1Gyr appear to form what might be termed a "cluster thick disk", part of which consists of objects that were probably captured gravitationally by the main body of the Galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A25
- Title:
- Disc breaks across masses and wavelengths
- Short Name:
- J/A+A/596/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Breaks in the surface brightness profiles in the outer regions of galactic discs are thought to have formed by various internal (e.g. bar resonances) and external (e.g. galaxy merging) processes. By studying the disc breaks we aim to better understand what processes are responsible for the evolution of the outer discs of galaxies, and galaxies in general. We use a large well-defined sample to study how common the disc breaks are, and whether their properties depend on galaxy mass. By using both optical and infrared data we study whether the observed wavelength affects the break features as a function of galaxy mass and Hubble type. We studied the properties of galaxy discs using radial surface brightness profiles of 753 galaxies, obtained from the 3.6um images of the Spitzer Survey of Stellar Structure in Galaxies (S4G), and the Ks-band data from the Near InfraRed S0-Sa galaxy Survey (NIRS0S), covering a wide range of galaxy morphologies (-2<=T<=9) and stellar masses (8.5<~log10 (M*/M_{sun}_)<~11). In addition, optical Sloan Digital Sky Survey (SDSS) or Liverpool telescope data was used for 480 of these galaxies. We find that in low-mass galaxies the single exponential profiles (Type I) are most common, and that their fraction decreases with increasing galaxy stellar mass. The fraction of down-bending (Type II) profiles increases with stellar mass, possibly due to more common occurrence of bar resonance structures. The up-bending (Type III) profiles are also more common in massive galaxies. The observed wavelength affects the scalelength of the disc of every profile type. Especially the scalelength of the inner disc (h_i_) of Type II profiles increases from infrared to u-band on average by a factor of ~2.2. Consistent with the previous studies, but with a higher statistical significance, we find that Type II outer disc scalelengths (h_o_) in late-type and low mass galaxies (T>4, log10(M*/M_{sun}_)<~10.5) are shorter in bluer wavelengths, possibly due to stellar radial migration populating the outer discs with older stars. In Type III profiles h_o are larger in the u band, hinting to the presence of young stellar population in the outer disc. While the observed wavelength affects the disc parameters, it does not significantly affect the profile type classification in our sample. Our results indicate that the observed wavelength is a significant factor when determining the profile types in very low mass dwarf galaxies, for which more Type II profiles have been previously found using optical data.
