- ID:
- ivo://CDS.VizieR/J/ApJ/701/1965
- Title:
- Radial dust properties of SINGS galaxies
- Short Name:
- J/ApJ/701/1965
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed analysis of the radial distribution of dust properties in the SINGS sample, performed on a set of ultraviolet (UV), infrared (IR), and HI surface brightness profiles, combined with published molecular gas profiles and metallicity gradients. By applying physical dust models to our radial spectral energy distributions, we have derived radial profiles of the total dust mass surface density, the fraction of the total dust mass contributed by polycyclic aromatic hydrocarbons (PAHs), and the intensity of the radiation field heating the grains.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/694/1085
- Title:
- Radii of exoplanet host stars
- Short Name:
- J/ApJ/694/1085
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present interferometric angular sizes for 12 stars with known planetary companions, for comparison with 28 additional main-sequence stars not known to host planets. For all objects we estimate bolometric fluxes and reddenings through spectral-energy distribution (SED) fits, and in conjunction with the angular sizes, measurements of effective temperature. The angular sizes of these stars are sufficiently small that the fundamental resolution limits of our primary instrument, the Palomar Testbed Interferometer, are investigated at the sub-milliarcsecond level and empirically established based upon known performance limits. We demonstrate that the effective temperature scale as a function of dereddened (V-K)0 color is statistically identical for stars with and without planets. Additionally, in an Appendix we provide SED fits for the 166 stars with known planets which have sufficient photometry available in the literature for such fits; this derived "XO-Rad" database includes homogeneous estimates of bolometric flux, reddening, and angular size.
- ID:
- ivo://CDS.VizieR/J/ApJ/623/897
- Title:
- Reddening and extinction at high galactic latitude
- Short Name:
- J/ApJ/623/897
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared (JHKL) photometry of 103 southern stars located behind translucent interstellar clouds at high Galactic latitude. Our data are combined with visual photometry and spectral type information from the literature in a detailed analysis of the wavelength dependence of interstellar extinction by dust in these high-latitude clouds. We investigate the shape of the near-infrared extinction curve and evaluate the total line-of-sight extinction (A_V_) and ratio of total-to-selective extinction (R_V_) in each line of sight.
- ID:
- ivo://CDS.VizieR/J/A+AS/136/261
- Title:
- Reference stars for 12 low-extinction fields
- Short Name:
- J/A+AS/136/261
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table B contains the recommended reference stars for the 12 low-extinction fields towards the galactic bulge, that are the results of a extension of Tycho catalog (Cat. <I/239>, ESA, 1997) for these regions. The first column of the catalog indicates the star label, formed by a number that designates the window (see Table 1) and a sequential counter. The following columns contain the mean right ascension, the corresponding standard deviation (in seconds); the mean declination, its standard deviation (in arcseconds) (J2000); the weighted average magnitude, its standard deviation and weighted error. Stars belonging to the Tycho Catalogue are indicated with a "T" in the second column. We stress that, being a natural extension of the Tycho Catalogue, the Valinhos Reference Catalogue is not complete up to the given magnitude in that regions, but instead constitute a reference set which may prove useful for dedicated studies of low-extinction fields (Dominici, 1998, MSc. Thesis IAG/USP).
- ID:
- ivo://CDS.VizieR/J/ApJ/825/91
- Title:
- Refined classification for Orion A protostars
- Short Name:
- J/ApJ/825/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the list of young stellar objects (YSOs) compiled by Megeath et al. (2012, J/AJ/144/192) for the Orion A molecular cloud, only 44 out of 1208 sources found projected onto low extinction (A_K_<0.8mag) gas are identified as protostars. These objects are puzzling because protostars are not typically expected to be associated with extended low extinction material. Here, we use high resolution extinction maps generated from Herschel data, optical/infrared and Spitzer Space Telescope photometry and spectroscopy of the low extinction protostellar candidate sources to determine if they are likely true protostellar sources or contaminants. Out of 44 candidate objects, we determine that 10 sources are likely protostars, with the rest being more evolved YSOs (18), galaxies (4), false detections of nebulosity and cloud edges (9), or real sources for which more data are required to ascertain their nature (3). We find none of the confirmed protostars to be associated with recognizable dense cores and we briefly discuss possible origins for these orphaned objects.
- ID:
- ivo://CDS.VizieR/J/ApJ/776/26
- Title:
- RRab stars in the Orphan stream distances
- Short Name:
- J/ApJ/776/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report positions, velocities, and metallicities of 50 ab-type RR Lyrae (RRab) stars observed in the vicinity of the Orphan stellar stream. Using about 30 RRab stars classified as being likely members of the Orphan stream, we study the metallicity and the spatial extent of the stream. We find that RRab stars in the Orphan stream have a wide range of metallicities, from -1.5dex to -2.7dex. The average metallicity of the stream is -2.1dex, identical to the value obtained by Newberg et al. (2010ApJ...711...32N) using blue horizontal branch stars. We find that the most distant parts of the stream (40-50kpc from the Sun) are about 0.3dex more metal-poor than the closer parts (within ~30kpc), suggesting a possible metallicity gradient along the stream's length. We have extended the previous studies and have mapped the stream up to 55kpc from the Sun. Even after a careful search, we did not identify any more distant RRab stars that could plausibly be members of the Orphan stream. If confirmed with other tracers, this result would indicate a detection of the end of the leading arm of the stream. We have compared the distances of Orphan stream RRab stars with the best-fit orbits obtained by Newberg et al. We find that model 6 of Newberg et al. cannot explain the distances of the most remote Orphan stream RRab stars, and conclude that the best fit to distances of Orphan stream RRab stars and to the local circular velocity is provided by potentials where the total mass of the Galaxy within 60kpc is M_60_~2.7x10^11^M_{sun}_, or about 60% of the mass found by previous studies. More extensive modeling that would consider non-spherical potentials and the possibility of misalignment between the stream and the orbit is highly encouraged.
- ID:
- ivo://CDS.VizieR/J/ApJ/863/79
- Title:
- RR Lyrae cand. in the Galactic Center
- Short Name:
- J/ApJ/863/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep near-IR images from the VISTA Variables in the Via Lactea (VVV) Survey were used to search for RR Lyrae stars within 100 arcmin from the Galactic Center. A large sample of 960 RR Lyrae of type ab (RRab) stars were discovered. A catalog is presented featuring the positions, magnitudes, colors, periods, and amplitudes for the sample, in addition to estimated reddenings, distances, and metallicities, and measured individual relative proper motions. We use the reddening-corrected Wesenheit magnitudes, defined as W_Ks_=Ks-0.428x(J-Ks), in order to isolate bona fide RRL belonging to the Galaxy Center, finding that 30 RRab are foreground/background objects. We measure a range of extinctions from A_Ks_=0.19 to 1.75mag for the RRab in this region, finding that large extinction is the main cause of the sample incompleteness. The mean period is P=0.5446+/-0.0025d, yielding a mean metallicity of [Fe/H]=-1.30+/-0.01 ({sigma}=0.33)dex for the RRab sample in the Galactic Center region. The median distance for the sample is D=8.05+/-0.02kpc. We measure the RRab surface density using the less reddened region sampled here, finding a density of 1000 RRab/sq deg at a projected Galactocentric distance R_G_=1.6deg. Under simple assumptions, this implies a large total mass (M>10^9^M_{sun}_) for the old and metal-poor population contained inside RG. We also measure accurate relative proper motions, from which we derive tangential velocity dispersions of {sigma}V_l_=125.0 and {sigma}V_b_=124.1km/s along the Galactic longitude and latitude coordinates, respectively. The fact that these quantities are similar indicate that the bulk rotation of the RRab population is negligible, and implies that this population is supported by velocity dispersion. In summary, there are two main conclusions of this study. First, the population as a whole is no different from the outer bulge RRab, predominantly a metal-poor component that is shifted with respect to the Oosterhoff type I population defined by the globular clusters in the halo. Second, the RRab sample, as representative of the old and metal-poor stellar population in the region, has high velocity dispersions and zero rotation, suggesting a formation via dissipational collapse.
- ID:
- ivo://CDS.VizieR/J/ApJ/732/110
- Title:
- SDSS 2175{AA} extinction bump candidates
- Short Name:
- J/ApJ/732/110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report detections of 39 2175{AA} dust extinction bump candidates associated with strong MgII absorption lines at z~1-1.8 on quasar spectra in Sloan Digital Sky Survey (SDSS) DR3. These strong MgII absorption line systems are detected among 2951 strong MgII absorbers with a rest equivalent width W_r_{lambda}2796>1.0{AA} at 1.0<z<1.86, which is part of a full sample of 7421 strong MgII absorbers compiled by Prochter et al. (2006, Cat. J/ApJ/639/766). The redshift range of the absorbers is chosen to allow the 2175{AA} extinction features to be completely covered within the SDSS spectrograph operation wavelength range. An upper limit of the background quasar emission redshift at z=2.1 is set to prevent the Ly{alpha} forest lines from contaminating the sensitive spectral region for the 2175{AA} bump measurements. A total of 12 absorbers are detected with 2175{AA} bumps at a 5{sigma} level of statistical significance, 10 are detected at a 4{sigma} level, and 17 are detected at a 3{sigma} level. Most of the candidate bumps in this work are similar to the relatively weak 2175{AA} bumps observed in the Large Magellanic Cloud LMC2 supershell rather than the strong ones observed in the Milky Way.
- ID:
- ivo://CDS.VizieR/J/AJ/144/17
- Title:
- SDSS and CSP ugri photometry of 9 type Ia supernova
- Short Name:
- J/AJ/144/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Consistency between Carnegie Supernova Project (CSP) and SDSS-II Supernova Survey ugri measurements has been evaluated by comparing Sloan Digital Sky Survey (SDSS) and CSP photometry for nine spectroscopically confirmed Type Ia supernova observed contemporaneously by both programs. The CSP data were transformed into the SDSS photometric system. Sources of systematic uncertainty have been identified, quantified, and shown to be at or below the 0.023mag level in all bands. When all photometry for a given band is combined, we find average magnitude differences of equal to or less than 0.011mag in ugri, with rms scatter ranging from 0.043 to 0.077mag. The u-band agreement is promising, with the caveat that only four of the nine supernovae are well observed in u and these four exhibit an 0.038mag supernova-to-supernova scatter in this filter.
- ID:
- ivo://CDS.VizieR/J/A+A/599/A71
- Title:
- 209276 SDSS star-forming galaxies aperture-free
- Short Name:
- J/A+A/599/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Large area surveys with a high number of galaxies observed have undoubtedly marked a milestone in the understanding of several properties of galaxies, such as star-formation history, morphology, and metallicity. However, in many cases, these surveys provide fluxes from fixed small apertures (e.g. fibre), which cover a scant fraction of the galaxy, compelling us to use aperture corrections to study the global properties of galaxies. In this work, we derive the current total star formation rate (SFR) of Sloan Digital Sky Survey (SDSS) star-forming galaxies, using an empirically based aperture correction of the measured H{alpha} flux for the first time, thus minimising the uncertainties associated with reduced apertures. All the H{alpha} fluxes have been extinction-corrected using the H{alpha}/H{beta} ratio free from aperture effects. The total SFR for ~210000 SDSS star-forming galaxies has been derived applying pure empirical H{alpha} and H{alpha}/H{beta} aperture corrections based on the Calar Alto Legacy Integral Field Area (CALIFA) survey. We find that, on average, the aperture-corrected SFR is ~0.65dex higher than the SDSS fibre-based SFR. The relation between the SFR and stellar mass for SDSS star-forming galaxies (SFR-M*) has been obtained, together with its dependence on extinction and H{alpha} equivalent width. We compare our results with those obtained in previous works and examine the behaviour of the derived SFR in six redshift bins, over the redshift range 0.005<=z<=0.22. The SFR-M* sequence derived here is in agreement with selected observational studies based on integral field spectroscopy of individual galaxies as well as with the predictions of recent theoretical models of disc galaxies.
