- ID:
- ivo://CDS.VizieR/J/A+A/561/A33
- Title:
- SDSS star-forming galaxies multi-wavelength study
- Short Name:
- J/A+A/561/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied a large sample of ~14000 dwarf star-forming galaxies with strong emission lines. These low-metallicity galaxies with oxygen abundances of 12+logO/H~7.4-8.5 are selected from the Sloan Digital Sky Survey (SDSS) and distributed in the redshift range of z~0-0.6. We modelled spectral energy distributions (SED) of all galaxies, which were based on the SDSS spectra in the visible range of 0.38{mu}m-0.92{mu}m and included both the stellar and ionised gas emission. These SEDs were extrapolated to the UV and mid-infrared ranges to cover the wavelength range of 0.1{mu}m-22{mu}m. The SDSS spectroscopic data were supplemented by photometric data from the GALEX, SDSS, 2MASS, WISE, IRAS, and NVSS all-sky surveys. Using these data, we derived global characteristics of the galaxies, such as their element abundances, luminosities, and stellar masses.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/145/245
- Title:
- SDSS stars in Draco dwarf spheroidal galaxy
- Short Name:
- J/ApJS/145/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Sloan Digital Sky Survey (SDSS, Stoughton et al., 2002AJ....123..485S) has scanned the entire region containing the Draco dwarf spheroidal galaxy to 23mag in g*. We present a catalog of stars found in a 453 arcmin^2^, elliptical region centered on the Draco dwarf spheroidal galaxy. Objects in the catalog are matched with five previously published catalogs. The catalog contains SDSS photometry for 5634 individual objects, and also the photometry from matches to any of the other catalogs. A comparison of the photometry between catalogs allows us to identify 142 candidate variable objects. One hundred and twelve of the suspected variables have colors consistent with RR Lyrae variables.
- ID:
- ivo://CDS.VizieR/J/AJ/134/973
- Title:
- SDSS Stripe 82 star catalogs
- Short Name:
- J/AJ/134/973
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a standard star catalog constructed using multiple SDSS photometric observations (at least four per band, with a median of 10) in the ugriz system. The catalog includes 1.01 million nonvariable unresolved objects from the equatorial stripe 82 (|{delta}_J2000.0_|<1.266{deg}) in the right ascension range 20^h^34^m^-4^h^00^m^ and with the corresponding r-band (approximately Johnson V-band) magnitudes in the range 14-22. The distributions of measurements for individual sources demonstrate that the photometric pipeline correctly estimates random photometric errors, which are below 0.01mag for stars brighter than 19.5, 20.5, 20.5, 20, and 18.5 in ugriz, respectively (about twice as good as for individual SDSS runs). Several independent tests of the internal consistency suggest that the spatial variation of photometric zero points is not larger than ~0.01mag (rms). In addition to being the largest available data set with optical photometry internally consistent at the ~1% level, this catalog provides a practical definition of the SDSS photometric system. Using this catalog, we show that photometric zero points for SDSS observing runs can be calibrated within a nominal uncertainty of 2% even for data obtained through 1mag thick clouds, and we demonstrate the existence of He and H white dwarf sequences using photometric data alone. Based on the properties of this catalog, we conclude that upcoming large-scale optical surveys such as the Large Synoptic Survey Telescope will be capable of delivering robust 1% photometry for billions of sources.
- ID:
- ivo://CDS.VizieR/J/MNRAS/382/515
- Title:
- SDSS ultracool and halo WD candidates
- Short Name:
- J/MNRAS/382/515
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A 2.5x100{deg}^2^ region along the celestial equator (Stripe 82) has been imaged repeatedly from 1998 to 2005 by the Sloan Digital Sky Survey (SDSS). A new catalogue of ~4 million light-motion curves, together with over 200 derived statistical quantities, for objects in Stripe 82 brighter than r~21.5 has been constructed by combining these data by Bramich et al. (2008MNRAS.386..887B). This catalogue is at present the deepest catalogue of its kind. Extracting ~130000 objects with highest signal-to-noise ratio proper motions, we build a reduced proper motion diagram to illustrate the scientific promise of the catalogue. In this diagram, disc and halo subdwarfs are well-separated from the cool white dwarf sequence. Our sample of 1049 cool white dwarf candidates includes at least eight and possibly 21 new ultracool H-rich white dwarfs (Teff<4000K) and one new ultracool He-rich white dwarf candidate identified from their SDSS optical and UKIDSS infrared photometry. At least 10 new halo white dwarfs are also identified from their kinematics.
- ID:
- ivo://CDS.VizieR/J/AJ/125/2621
- Title:
- SDSS WD-M binary parameters
- Short Name:
- J/AJ/125/2621
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified 109 white dwarf (WD)-M dwarf pairs in the Sloan Digital Sky Survey (SDSS) with g<20th magnitude. For each system we determined the temperature of the WD primary and the spectral type of the M dwarf secondary. Using H{alpha} emission as a proxy for the chromospheric activity level of the M dwarf, we investigated correlations between the activity level and properties of the system. Compared with field M dwarfs previously observed in the Palomar/MSU Survey, we see a slightly higher active fraction of early-type stars, with activity levels similar to the field. We have conducted follow-up observations at the ARC 3.5m telescope to obtain radial velocity information and to search for short-period binaries that may be on the verge of interacting. We report on one system with a 4.1hr period and several additional systems with significant velocity variations.
- ID:
- ivo://CDS.VizieR/J/ApJ/815/63
- Title:
- SDSS wide double white dwarfs spectroscopy
- Short Name:
- J/ApJ/815/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observational constraints on the initial-final mass relation (IFMR) using wide double white dwarfs (DWDs). We identify 65 new candidate wide DWDs within the Sloan Digital Sky Survey, bringing the number of candidate wide DWDs to 142. We then engage in a spectroscopic follow-up campaign and collect existing spectra for these objects; using these spectra, we derive masses and cooling ages for 54 hydrogen (DA) WDs in DWDs. We also identify one new DA/DB pair, four candidate DA/DC pairs, four candidate DA/DAH pairs, and one new candidate triple degenerate system. Because wide DWDs are co-eval and evolve independently, the difference in the pre-WD lifetimes should equal the difference in the WD cooling ages. We use this to develop a Bayesian hierarchical framework and construct a likelihood function to determine the probability that any particular IFMR fits a sample of wide DWDs. We then define a parametric model for the IFMR and find the best parameters indicated by our sample of DWDs. We place robust constraints on the IFMR for initial masses of 2-4M_{sun}_. The WD masses produced by our model for stars within this mass range differ from those predicted by semi-empirical fits to open cluster WDs. Within this mass range, where there are few constraining open cluster WDs and disagreements in the cluster ages, wide DWDs may provide more reliable constraints on the IFMR. Expanding this method to the many wide DWDs expected to be discovered by Gaia may transform our understanding of the IFMR.
- ID:
- ivo://CDS.VizieR/J/ApJ/884/82
- Title:
- SDSS, WISE and HI data of local spiral galaxies
- Short Name:
- J/ApJ/884/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The emerging light from a galaxy is under the influence of its own interstellar medium, as well as its spatial orientation. Considering a sample of 2239 local spiral galaxies in optical (Sloan Digital Sky Survey u, g, r, i, and z) and infrared bands (WISE W1, W1), we study the dependency of the global intrinsic attenuation in spiral galaxies on their morphologies, sizes, and spatial inclinations. Reddening is minimal at the extremes of low mass and gas depletion and maximal in galaxies that are relatively massive and metal-rich and still retain substantial gas reserves. A principal component constructed from observables that monitor galaxy mass, relative H i content to old stars, and infrared surface brightness is strongly correlated with the amplitude of obscuration. We determine both a parametric model for dust obscuration and a nonparametric model based on the Gaussian process formalism. An average dust attenuation curve is derived for wavelengths between 0.36 and 4.5{mu}m.
- ID:
- ivo://CDS.VizieR/J/ApJ/856/6
- Title:
- SEAMBHs IX. 10 new H{beta} light curves
- Short Name:
- J/ApJ/856/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As one paper in a series reporting on a large reverberation mapping campaign of super-Eddington accreting massive black holes (SEAMBHs) in active galactic nuclei (AGNs), we present the results of 10 SEAMBHs monitored spectroscopically during 2015-2017. Six of them are observed for the first time, and have generally higher 5100{AA} luminosities than the SEAMBHs monitored in our campaign from 2012 to 2015; the remaining four are repeat observations to check if their previous lags change. Similar to the previous SEAMBHs, the H{beta} time lags of the newly observed objects are shorter than the values predicted by the canonical RH{beta}-L5100 relation of sub-Eddington AGNs, by factors of ~2-6, depending on the accretion rate. The four previously observed objects have lags consistent with previous measurements. We provide linear regressions for the RH{beta}-L5100 relation, solely for the SEAMBH sample and for low-accretion AGNs. We find that the relative strength of Fe ii and the profile of the H{beta} emission line can be used as proxies of accretion rate, showing that the shortening of H{beta} lags depends on accretion rates. The recent SDSS-RM discovery of shortened H{beta} lags in AGNs with low accretion rates provides compelling evidence for retrograde accretion onto the black hole. These evidences show that the canonical RH{beta}-L5100 relation holds only in AGNs with moderate accretion rates. At low accretion rates, it should be revised to include the effects of black hole spin, whereas the accretion rate itself becomes a key factor in the regime of high accretion rates.
- ID:
- ivo://CDS.VizieR/J/ApJS/241/6
- Title:
- Searching for super-fast rotators using PS1
- Short Name:
- J/ApJS/241/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A class of asteroids, called large super-fast rotators (large SFRs), have rotation periods shorter than 2hr and diameters larger than ~0.3km. They pose challenges to the usual interior rubble-pile structure unless a relatively high bulk density is assumed. So far, only six large SFRs have been found. Therefore, we present a survey of asteroid rotation periods using the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) 1 telescope during 2016 October 26-31 to search for more large SFRs and to study their properties. A total of 876 reliable rotation periods are measured, among which seven are large SFRs, thereby increasing the inventory of known large SFRs. These seven newly discovered large SFRs have diverse colors and locations in the main asteroid belt, suggesting that the taxonomic tendency and the location preference in the inner main belt of the six previously known large SFRs could be a bias due to various observational limits. Interestingly, five out of the seven newly discovered large SFRs are mid main-belt asteroids (MBAs). Considering the rare discovery rates of large SFR in the previously similar surveys and the survey condition in this work, the chance of detecting a large SFR in the inner main belt seems to be relatively low. This probably suggests that the inner main belt harbors fewer large SFRs than the mid main belt. From our survey, we also found a drop in the number appearing at f>5rev/day on the spin-rate distribution for the outer MBAs of D<3km, which was reported for the inner and mid main belt by Chang et al. (2015, J/ApJS/219/27 ; 2016ApJ...816...71C).
- ID:
- ivo://CDS.VizieR/J/AJ/134/1890
- Title:
- Secondary standard stars in u'g'r'i'z'
- Short Name:
- J/AJ/134/1890
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new set of secondary standard stars for the u'g'r'i'z' photometric system that has been established in selected open and globular star clusters. These standards are calibrated to the original standard system defined by Smith et al. with an accuracy of 1% or better, extend as faint as r'~20, and are concentrated in small regions of the sky. As a result, they can serve as viable calibrators of photometry obtained on some of the large-aperture, high-demand telescopes that employ the u'g'r'i'z' filter set.
