- ID:
- ivo://CDS.VizieR/VIII/39
- Title:
- Composite CO Survey of the Milky Way
- Short Name:
- VIII/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This survey consists of CO(J=1-0) (115 GHz) spectra for the entire Galactic plane. The latitude coverage varies with longitude and in some regions extends from -25 degrees to +25 degrees. The observations were made with the Columbia/GISS 1.2m telescope in New York City, and a twin telescope on Cerro Tololo in Chile. The angular resolution of the survey is 30' (square), the velocity resolution is 1.3km/s and the sensitivity ranges from about 0.1K/chan to 0.35K/chan. The survey is presented as 720 latitude-velocity maps in FITS format, one for each 30' of longitude from -180.0 deg to +179.5 deg, and one velocity-integrated map covering the entire plane. The velocity range of each file is -300 km/s to +300 km/s. The survey has been updated to include some additional data, more careful reprojections of the regions that were originally mapped in equatorial coordinates, and improved estimates of the absolute calibration of the CO intensities (Digel and Dame 1995, unpublished).
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- ID:
- ivo://CDS.VizieR/J/ApJ/475/469
- Title:
- Composite HST Spectrum of Quasars
- Short Name:
- J/ApJ/475/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We construct a composite quasar spectrum from 284 HST FOS spectra of 101 quasars with redshifts z>0.33. The spectrum covers the wavelengths between 350 and 3000A in the rest frame, with a peak S/N level of ~130 per A at ~1200A. Since ~90% of the sample quasars have redshift z<1.5, the spectrum is suitable for studying the wavelength region shortward of Ly{alpha} without large effects from intervening Ly{alpha} forest absorption. Data in the waveband between 350 and 600A are mainly from the spectra of z>1.5 quasars, for which significant corrections for the accumulated Lyman-series line and continuum absorption have been applied. There is a significant steepening of the continuum slope around 1050A. The continuum between 1050 and 2200A can be modeled as a power law f_{nu} proportional to {nu}_{alpha}_ with {alpha}=-0.99+/-0.05. For the full sample the power-law index in the extreme ultraviolet (EUV) between 350 and 1050A is {alpha}=-1.96+/-0.15. For the radio-loud subsample (60 objects), the EUV spectral index is {alpha}~=-2.2, while for the radio-quiet subsample (41 objects) it is {alpha}~=-1.8. The continuum flux in the wavelengths near the Lyman limit shows a depression of ~10%. The break in the power-law index and the slight depression of the continuum near the Lyman limit are features expected in Comptonized accretion-disk spectra. Comptonization produces a power-law tail in the wavelength band shortward of 1000A and smears out the Lyman-limit edge of the intrinsic accretion-disk spectrum. In the EUV waveband, we detect several possible emission features, including one around 690A that may be O III + N III produced by the Bowen fluorescence effect. Comparing our composite spectrum with one made at higher redshifts by Francis et al. (1991ApJ...373..465F), we find that the equivalent widths of Ly{alpha} and high-ionization emission lines are larger in our sample, reflecting a known luminosity dependence. The equivalent widths of low-ionization lines do not exhibit such a dependence, suggesting that the quasar EUV continuum above ~50eV is steeper at higher luminosity. Radio-quiet quasars appear to show a slightly harder continuum and lower ionization levels in their emission lines.
- ID:
- ivo://CDS.VizieR/J/ApJ/849/53
- Title:
- Composite SEDs of type 1 and type 2 QSOs
- Short Name:
- J/ApJ/849/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observed mid-infrared and optical colors and composite spectral energy distributions (SEDs) of type 1 (broad-line) and 2 (narrow-line) quasars selected from Sloan Digital Sky Survey (SDSS) spectroscopy. A significant fraction of powerful quasars are obscured by dust and are difficult to detect in optical photometric or spectroscopic surveys. However, these may be more easily identified on the basis of mid-infrared (MIR) colors and SEDs. Using samples of SDSS type 1 and 2 matched in redshift and [OIII] luminosity, we produce composite rest-frame 0.2-15{mu}m SEDs based on SDSS, UKIDSS, and Wide-field Infrared Survey Explorer photometry and perform model fits using simple galaxy and quasar SED templates. The SEDs of type 1 and 2 quasars are remarkably similar, with the differences explained primarily by the extinction of the quasar component in the type 2 systems. For both types of quasar, the flux of the active galactic nucleus (AGN) relative to the host galaxy increases with AGN luminosity (L_[OIII]_) and redder observed MIR color, but we find only weak dependencies of the composite SEDs on mechanical jet power as determined through radio luminosity. We conclude that luminous quasars can be effectively selected using simple MIR color criteria similar to those identified previously (W1-W2>0.7; Vega), although these criteria miss many heavily obscured objects. Obscured quasars can be further identified based on optical-IR colors (for example, (u-W3[AB]>1.4(W1-W2[Vega])+3.2). These results illustrate the power of large statistical studies of obscured quasars selected on the basis of MIR and optical photometry.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1288
- Title:
- Composite spectra of early-type galaxies
- Short Name:
- J/AJ/131/1288
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Chemical abundance indicators are studied using composite spectra, which we provide in tabular form. Tables of line strengths measured from these spectra and parameters derived from these line strengths are also provided. All the objects we analyze were selected from the SDSS database. We selected all objects targeted as galaxies and having Petrosian apparent magnitude 14.5<=r_Pet_<=17.75. To extract a sample of early-type galaxies, we then chose the subset with the spectroscopic parameter eclass<0, which classifies the spectral type based on a principal component analysis, and the photometric parameter fracDev_r_>0.8, which is a seeing-corrected indicator of morphology.
- ID:
- ivo://CDS.VizieR/J/A+A/276/142
- Title:
- Compositional differences among the A-type stars
- Short Name:
- J/A+A/276/142
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
3826. ComPRASS catalogue
- ID:
- ivo://CDS.VizieR/J/A+A/626/A7
- Title:
- ComPRASS catalogue
- Short Name:
- J/A+A/626/A7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first all-sky catalogue of galaxy clusters and cluster candidates obtained from joint X-ray-SZ detections using observations from the Planck satellite and the ROSAT all-sky survey (RASS). The catalogue contains 2323 objects and has been validated by careful cross-identification with previously known clusters. This validation shows that 1597 candidates correspond to already known clusters, 212 coincide with other cluster candidates still to be confirmed, and the remaining 514 are completely new detections. With respect to Planck catalogues, the ComPRASS catalogue is simultaneously more pure and more complete. Based on the validation results in the SPT and SDSS footprints, the expected purity of the catalogue is at least 84.5%, meaning that more than 365 clusters are expected to be found among the new or still-to-be-confirmed candidates with future validation efforts or specific follow-ups.
- ID:
- ivo://CDS.VizieR/VII/262
- Title:
- Comprehensive Catalogue of Kiso UV-X Galaxies (KUG2000)
- Short Name:
- VII/262
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The referenced paper describes the compilation of the second Kiso UV-Excess galaxies survey as KUG2 catalogue. The result is shown in VII/261. The first survey catalogue KUG1 is shown in VII/179. As is described in the paper, there are some differences between KUG1 and KUG2, e.g. in photographic plates used and the observation condition in the surveys, such as emulsions, exposures or seeing sizes. The homogeneity of these KUG surveys is rather low, but their catalogues form a somewhat large collection of UV-excess/blue galaxies. In these circumstances, we intend to merge both catalogues, upon requests from investigators working in follow-up observations of these galaxies. In the process of catalogue merging, we met a systematic difference between the first (KUG1) and the second (KUG2) surveys in overall properties of objects, such as brightness, degree of UV-excess and morphological type. This mainly originates from differences in the observation condition and personal errors in the survey. We scrutinize and discuss those differences and errors, and finally merge into a comprehensive catalogue of KUGs (KUG2000) in the machine-readable form including near ten thousand UV-excess galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/397/711
- Title:
- Comptonization and reflection in GRS 1915+105
- Short Name:
- J/A+A/397/711
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive X-ray study of four years of pointed RXTE observations of GRS 1915+105 in the {chi}-state. We interpret the behavior of the hard power law tail spectrum as coming from inverse Compton scattering of soft disk photons on a thermally dominated hybrid corona above the accretion disk. GRS 1915+105 shows a strong, variable reflection amplitude. As in other BHC and in Seyfert galaxies, a correlation between the power law slope and the reflection was found. Also, the radio fluxes at 2.25GHz and 15GHz correlate with the power law slope, thus revealing a connection between the outflowing matter and the comptonizing region in the {chi}-states.
- ID:
- ivo://CDS.VizieR/J/ApJ/815/L13
- Title:
- Compton-thick AGNs from the 70-month Swift/BAT cat.
- Short Name:
- J/ApJ/815/L13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Heavily obscured accretion is believed to represent an important stage in the growth of supermassive black holes and to play an important role in shaping the observed spectrum of the cosmic X-ray background. Hard X-ray (E>10keV) selected samples are less affected by absorption than samples selected at lower energies, and are therefore one of the best ways to detect and identify Compton-thick (CT, logN_H_>=24) active galactic nuclei (AGNs). In this letter we present the first results of the largest broadband (0.3-150keV) X-ray spectral study of hard X-ray selected AGNs to date, focusing on the properties of heavily obscured sources. Our sample includes the 834 AGNs (728 non-blazar, average redshift z~0.055) reported in the 70-month catalog of the all-sky hard X-ray Swift/Burst Alert Monitor survey. We find 55 CT AGNs, which represent 7.6_-2.1_^+1.1^% of our non-blazar sample. Of these, 26 are reported as candidate CT AGNs for the first time. We correct for selection bias and derive the intrinsic column density distribution of AGNs in the local universe in two different luminosity ranges. We find a significant decrease in the fraction of obscured Compton-thin AGNs for increasing luminosity, from 46+/-3% (for logL_14-195_=40-43.7) to 39+/-3% (for logL_14-195_=43.7-46). A similar trend is also found for CT AGNs. The intrinsic fraction of CT AGNs with logN_H_=24-25 normalized to unity in the logN_H_=20-25 range is 27+/-4%, and is consistent with the observed value obtained for AGNs located within 20Mpc.
- ID:
- ivo://CDS.VizieR/J/A+A/454/333
- Title:
- Computed Hbeta indices from ATLAS9 model
- Short Name:
- J/A+A/454/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Grids of H{beta} indices based on updated (new-ODF) ATLAS9 model atmospheres were computed for solar and scaled solar metallicities [+0.5], [+0.2], [0.0], [-0.5], [-1.0], [-1.5], [-2.0], [-2.5] and for alpha enhanced compositions [+0.5a], [0.0a], [-0.5a], [-1.0a], [-1.5a], [-2.0a], [-2.5a], and [-4.0a]. Indices for Teff>5000K were computed with the same methods as described by Lester, Gray & Kurucz (1986ApJS...61..509L) (LGK86) except for a different normalization of the computed natural system to the standard system. LGK86 used special ODFs to compute the fluxes. For Teff less or equal to 5000K we computed the fluxes using the synthetic spectrum method. In order to assess the accuracy of the computed indices comparisons were made with the indices computed by Smalley & Dworetsky (1995A&A...293..446S) (MD95) and with the empirical relations Teff-H{beta} given by Alonso et al. (1996A&A...313..873A) for several metallicities. Furthermore, for cool stars, temperatures inferred from the computed indices were compared with those of the fundamental stars listed by MD95. The same kind of comparison was made between gravities for B-type stars. The temperatures from the computed indices are in good agreement, within the error limits, with the literature values for Teff between 4750K and 8000K, while the gravities agree for Teff>9000K. The computed H{beta} indices for the Sun and for Procyon are very close to the observed values. The comparison between the observed and computed H{beta} indices as function of the observed H{beta} has shown a very small trend which almost completely disappears when only stars hotter than 10000K are considered. The trend due to the cool stars is probably related with the low accuracy of the fundamental Teff which are affected by large errors for most of the stars.