- ID:
- ivo://CDS.VizieR/J/ApJ/679/239
- Title:
- Associated MgII absorbers
- Short Name:
- J/ApJ/679/239
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied a sample of 415 associated (z_abs_~z_em_; relative velocity with respect to QSO in units of c, {beta}<0.01) MgII absorption systems with 1.0<=z_abs_<=1.86, in the spectra of SDSS DR3 QSOs, to determine the dust content and ionization state in the absorbers. We also compared these properties to those of a similarly selected sample of 809 intervening systems ({beta}>0.01), so as to understand their origin. Normalized, composite spectra were derived for absorption line measurements, for the full sample and for several subsamples, chosen on the basis of the line strengths and other absorber and QSO properties. From these, and from the equivalent widths in individual spectra, we conclude that the associated MgII absorbers have higher ionization (higher ratios of the strengths of CIV and MgII lines), than the intervening absorbers. The ionization decreases with increasing {beta}. Average extinction curves were obtained for the subsamples by comparing their geometric mean QSO spectra with those of matching (in z_em_ and i magnitude) samples of QSOs without absorption lines. There is clear evidence for SMC-like dust attenuation in these systems; the 2175{AA} absorption feature is absent. The extinction is almost twice that observed in intervening systems. We reconfirm that QSOs with nonzero FIRST radio flux are intrinsically redder than the QSOs with no detection in the FIRST survey.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/284/233
- Title:
- Association of HII regions and IRAS PSC sources
- Short Name:
- J/A+A/284/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJ/753/83
- Title:
- Associations to 1FGL sources
- Short Name:
- J/ApJ/753/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Fermi Large Area Telescope (LAT) First Source Catalog (1FGL) provided spatial, spectral, and temporal properties for a large number of {gamma}-ray sources using a uniform analysis method. After correlating with the most-complete catalogs of source types known to emit {gamma} rays, 630 of these sources are "unassociated" (i.e., have no obvious counterparts at other wavelengths). Here, we employ two statistical analyses of the primary {gamma}-ray characteristics for these unassociated sources in an effort to correlate their {gamma}-ray properties with the active galactic nucleus (AGN) and pulsar populations in 1FGL. Based on the correlation results, we classify 221 AGN-like and 134 pulsar-like sources in the 1FGL unassociated sources. The results of these source "classifications" appear to match the expected source distributions, especially at high Galactic latitudes. While useful for planning future multiwavelength follow-up observations, these analyses use limited inputs, and their predictions should not be considered equivalent to "probable source classes" for these sources. We discuss multiwavelength results and catalog cross-correlations to date, and provide new source associations for 229 Fermi-LAT sources that had no association listed in the 1FGL catalog. By validating the source classifications against these new associations, we find that the new association matches the predicted source class in ~80% of the sources.
- ID:
- ivo://CDS.VizieR/J/PASP/116/1012
- Title:
- A star catalog for the open cluster NGC 188
- Short Name:
- J/PASP/116/1012
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new BVRI broadband photometry for the old open cluster NGC 188, based on an analysis of 299 CCD images either obtained by us, donated by colleagues, or retrieved from public archives.
- ID:
- ivo://CDS.VizieR/J/ApJ/722/605
- Title:
- A stellar rotation census of B stars
- Short Name:
- J/ApJ/722/605
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Two recent observing campaigns provide us with moderate dispersion spectra of more than 230 cluster and 370 field B stars. Combining them and the spectra of the B stars from our previous investigations (~430 cluster and ~100 field B stars) yields a large, homogeneous sample for studying the rotational properties of B stars. We derive the projected rotational velocity vsini, effective temperature, gravity, mass, and critical rotation speed V_crit_ for each star. We compare the evolutionary trends of rotation (measured according to the polar gravity of the star) with recent models that treat internal mixing.
- ID:
- ivo://CDS.VizieR/J/ApJS/226/21
- Title:
- ASTEP catalog of EB* and variable stars
- Short Name:
- J/ApJS/226/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the large photometric database of the ASTEP program, whose primary goal was to detect exoplanets in the southern hemisphere from Antarctica, to search for eclipsing binaries (EcBs) and variable stars. 673 EcBs and 1166 variable stars were detected, including 31 previously known stars. The resulting online catalogs give the identification, the classification, the period, and the depth or semi-amplitude of each star. Data and light curves for each object are available at http://astep-vo.oca.eu/.
- ID:
- ivo://CDS.VizieR/J/A+A/375/275
- Title:
- Asteroidal I, J, K in the DENIS Survey
- Short Name:
- J/A+A/375/275
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I, J, K magnitudes of 1233 asteroids (numbered between 1 and 8000) are presented here. These asteroids have been recovered in the DENIS Survey (Deep European Near-Infrared southern sky Survey) on the basis of their predicted ephemerides. The observations were performed with the 1m-telescope at ESO, La Silla (Chile). The limiting magnitudes of the three bands I, J, K centered at 0.8, 1.25 and 2.15 microns are respectively 18.5, 16.5 and 13.5.
- ID:
- ivo://CDS.VizieR/J/A+A/423/381
- Title:
- Asteroidal I, J, K in the DENIS Survey
- Short Name:
- J/A+A/423/381
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I, J, K magnitudes of 767 asteroids (numbered between 1 and 8000) are presented here. These asteroids have been recovered in the DENIS Survey (Deep European Near-Infrared southern sky Survey) on the basis of their predicted ephemerides. The observations were performed with the 1m-telescope at ESO, La Silla (Chile). The limiting magnitudes of the three bands I, J, K centered at 0.8, 1.25 and 2.15 microns are respectively 18.5, 16.5 and 13.5.
- ID:
- ivo://CDS.VizieR/J/A+A/641/A80
- Title:
- Asteroid (31) Euphrosyne R-band images
- Short Name:
- J/A+A/641/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Asteroid (31) Euphrosyne is one of the biggest objects in the asteroid main belt and it is also the largest member of its namesake family. The Euphrosyne family occupies a highly inclined region in the outer main belt and contains a remarkably large number of members, which is interpreted as an outcome of a disruptive cratering event.The goals of this adaptive-optics imaging study are threefold: to characterize the shape of Euphrosyne, to constrain its density, and to search for the large craters that may be associated with the family formation event. We obtained disk-resolved images of Euphrosyne using SPHERE/ZIMPOL at the ESO 8.2m VLT as part of our large program (ID: 199.C-0074, PI: Vernazza). We reconstructed its 3D shape via the ADAM shape modeling algorithm based on the SPHERE images and the available light curves of this asteroid. We analyzed the dynamics of the satellite with the \genoid meta-heuristic algorithm. Finally, we studied the shape of Euphrosyne using hydrostatic equilibrium models. Our SPHERE observations show that Euphrosyne has a nearly spherical shape with the sphericity index of 0.9888 and its surface lacks large impact craters. Euphrosyne's diameter is 268+/-6km, making it one of the top ten largest main belt asteroids. We detected a satellite of Euphrosyne - S/2019 (31) 1 - that is about 4 km across, on a circular orbit. The mass determined from the orbit of the satellite together with the volume computed from the shape model imply a density of 1665+/-242kg/m^-3^, suggesting that Euphrosyne probably contains a large fraction of water ice in its interior. We find that the spherical shape of Euphrosyne is a result of the reaccumulation process following the impact, as in the case of (10)Hygiea. However, our shape analysis reveals that, contrary to Hygiea, the axis ratios of Euphrosyne significantly differ from those suggested by fluid hydrostatic equilibrium following reaccumulation.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A121
- Title:
- Asteroid (7) Iris Deconvolved disk-resolved images
- Short Name:
- J/A+A/624/A121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Asteroid (7) Iris is an ideal target for disk-resolved imaging owing to its brightness (V~7-8) and large angular size of 0.33'' during its apparitions. Iris is believed to belong to the category of large unfragmented asteroids that avoided internal differentiation, implying that its current shape and topography may record the first few 100Myr of the solar system's collisional evolution. We recovered information about the shape and surface topography of Iris from disk-resolved VLT/SPHERE/ZIMPOL images acquired in the frame of our ESO large program. We used the All-Data Asteroid Modeling (ADAM) shape reconstruction algorithm to model the 3D shape of Iris, using optical disk-integrated data and disk-resolved images from SPHERE and earlier AO systems as inputs. We analyzed the SPHERE images and our model to infer the asteroid's global shape and the morphology of its main craters. Results. We present the 3D shape, volume-equivalent diameter D_eq_=214+/-5km, and bulk density {rho}=2.7+/-0.3g/cm^3^ of Iris. Its shape appears to be consistent with that of an oblate spheroid with a large equatorial excavation. We identified eight putative surface features 20-40km in diameter detected at several epochs, which we interpret as impact craters, and several additional crater candidates. Craters on Iris have depth-to-diameter ratios that are similar to those of analogous 10km craters on Vesta. The bulk density of Iris is consistent with that of its meteoritic analog based on spectroscopic observations, namely LL ordinary chondrites. Considering the absence of a collisional family related to Iris and the number of large craters on its surface, we suggest that its equatorial depression may be the remnant of an ancient (at least 3Gyr) impact. Iris's shape further opens the possibility that large planetesimals formed as almost perfect oblate spheroids. Finally, we attribute the difference in crater morphology between Iris and Vesta to their different surface gravities, and the absence of a substantial impact-induced regolith on Iris.