- ID:
- ivo://CDS.VizieR/J/ApJ/836/137
- Title:
- Deep, wide-field g,i imaging of And XXXI
- Short Name:
- J/ApJ/836/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from WIYN pODI imaging of Lacerta I (And XXXI), a satellite dwarf galaxy discovered in the outskirts of the Andromeda galaxy (M31) in Pan-STARRS1 survey data. Our deep, wide-field g,i photometry reaches ~3mag fainter than the photometry in the Pan-STARRS1 discovery paper and allows us to trace the stellar population of Lac I beyond two half-light radii from the galaxy center. We measure a Tip of the Red Giant Branch distance for Lac I of (m-M)_0_=24.44+/-0.11mag (773+/-40kpc, or 264+/-6kpc from M31), which is consistent with the Pan-STARRS1 distance. We use a maximum-likelihood technique to derive structural properties for the galaxy, and find a half-light radius (r_h_) of 3.24+/-0.21' (728+/-47pc), ellipticity ({epsilon}) of 0.44+/-0.03, total magnitude M_V_=-11.4+/-0.3, and central surface brightness {mu}_V,0_=24.8+/-0.3mag/arcsec^2^. We find no H I emission in archival data and set a limit on Lac I's neutral gas mass-to-light ratio of M_HI_/L_V_<0.06M_{sun}_/L_{sun}_, confirming Lac I as a gas-poor dwarf spheroidal galaxy. Photometric metallicities derived from Red Giant Branch stars within 2 r_h_ yield a median [Fe/H] of -1.68+/-0.03, which is more metal-rich than the spectroscopically derived value from Martin+ (2014ApJ...793L..14M). Combining our measured magnitude with this higher metallicity estimate places Lac I closer to its expected position on the luminosity-metallicity relation for dwarf galaxies.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/858/77
- Title:
- DEIMOS 10K spectroscopic survey in COSMOS field
- Short Name:
- J/ApJ/858/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 10718 objects in the COSMOS field, observed through multi-slit spectroscopy with the Deep Imaging Multi-Object Spectrograph (DEIMOS) on the Keck II telescope in the wavelength range ~5500-9800{AA}. The catalog contains 6617 objects with high-quality spectra (two or more spectral features), and 1798 objects with a single spectroscopic feature confirmed by the photometric redshift. For 2024 typically faint objects, we could not obtain reliable redshifts. The objects have been selected from a variety of input catalogs based on multi-wavelength observations in the field, and thus have a diverse selection function, which enables the study of the diversity in the galaxy population. The magnitude distribution of our objects is peaked at I_AB_~23 and K_AB_~21, with a secondary peak at K_AB_~24. We sample a broad redshift distribution in the range 0<z<6, with one peak at z~1, and another one around z~4. We have identified 13 redshift spikes at z>0.65 with chance probabilities <4x10^-4^, some of which are clearly related to protocluster structures of sizes >10Mpc. An object-to-object comparison with a multitude of other spectroscopic samples in the same field shows that our DEIMOS sample is among the best in terms of fraction of spectroscopic failures and relative redshift accuracy. We have determined the fraction of spectroscopic blends to about 0.8% in our sample. This is likely a lower limit and at any rate well below the most pessimistic expectations. Interestingly, we find evidence for strong lensing of Ly{alpha} background emitters within the slits of 12 of our target galaxies, increasing their apparent density by about a factor of 4.
- ID:
- ivo://CDS.VizieR/J/A+A/441/631
- Title:
- {Delta}a photometry of CP stars
- Short Name:
- J/A+A/441/631
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have summarized all {Delta}a measurements for galactic field stars (1474 objects) from the literature published over more than two decades. These measurements were, for the first time, compiled and homogeneously analyzed. The {Delta}a intermediate band photometric system samples the depth of the 5200{AA} flux depression by comparing the flux at the center with the adjacent regions with bandwidths of 110{AA} to 230{AA}. Because it was slightly modified over the last three decades, we checked for systematic trends for the different measurements but found no correlations whatsoever. The {Delta}a photometric system is most suitable to detecting magnetic chemically peculiar (CP) stars with high efficiency, but is also capable of detecting a small percentage of non-magnetic CP objects. Furthermore, the groups of (metal-weak) lambda Bootis, as well as classical Be/shell stars, can be successfully investigated. In addition, we also analyzed the behaviour of supergiants (luminosity class I and II). On the basis of apparent normal type objects, the correlation of the 3sigma significance limit and the percentage of positive detection for all groups was derived.
944. Delta Scuti stars
- ID:
- ivo://CDS.VizieR/J/A+AS/144/469
- Title:
- Delta Scuti stars
- Short Name:
- J/A+AS/144/469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An extensive and up-dated list of {delta} Sct stars is presented here. More than 500 papers, published during the last few years, have been revised and 341 new variables have been added to our last list, six years ago. This catalogue is intended to be a comprehensive review on the observational characteristics of all the {delta} Sct stars known until now, including stars contained in earlier catalogues together with other new discovered variables, covering information published until January 2000. In summary, 636 variables, 1149 references and 182 individual notes are presented in this new list.
- ID:
- ivo://CDS.VizieR/J/PASP/106/1120
- Title:
- Delta Scuti variables. II. DY Her
- Short Name:
- J/PASP/106/1120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second paper in a series on large-amplitude delta Scuti stars intended to determine Baade-Wesselink radii and luminosities with precision. The first paper (Wilson et al., 1993PASP..105..809W) discussed our method of analysis and its application to EH Librae; in this we discuss the observations and analysis of DY Herculis. Optical and infrared photometry and cross-correlated radial-velocity data have been obtained and analyzed. Fourier representations for the UBVRIJHK light curves and for the radial-velocity curves were used to derive a value for the minimum radius for each of 60 combinations of flux and color index. From these we adopt a mean value for the minimum radius of R_min_=2.77+/-0.20R_{sun}_. When combined with effective temperatures from Breger et al. (1978PASP...90..754B), we find a mean bolometric luminosity of <L_B_>=21.70L_{sun}_ and a mean absolute magnitude of <M_B_>=1.41. The radial excursion is 0.149R_{sun}_. We use the same procedure to improve our results for EH Librae, deriving R_min_ for each of 42 combinations of flux and color index, and obtain mean values of R_min_=2.62+/-0.19R_{sun}_, <L_B_>=24.56L_{sun}_ and <M_B_>=1.27.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A114
- Title:
- Detached eclipsing binaries MITSuME photometry
- Short Name:
- J/A+A/622/A114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of the combined photometric and spectroscopic analysis of three detached eclipsing binaries (DEBs), the secondary components of which are not visible or are very hard to identify in the optical spectra - ASAS J052743-0359.7, ASAS J065134-2211.5, and ASAS J073507-0905.7. The first one is the known visual binary ADS~4022, and we found that it is a quadruple system composed of two spectroscopic binaries, one of which shows eclipses.
- ID:
- ivo://CDS.VizieR/J/ApJ/872/85
- Title:
- Detached eclipsing binaries with Gaia parallaxes
- Short Name:
- J/ApJ/872/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a sample of 81 Galactic, detached eclipsing binary stars we investigated the global zero-point shift of their parallaxes with the Gaia Data Release 2 (DR2) parallaxes. The stars in the sample lay in a distance range of 0.04-2kpc from the Sun. The photometric parallaxes {omega}_Phot_ of the eclipsing binaries were determined by applying a number of empirical surface brightness-color (SBC) relations calibrated on optical-infrared colors. For each SBC relation we calculated the individual differences d{varpi}_i_=({varpi}_Gaia_-{varpi}_Phot_)_i_ and then we calculated unweighted and weighted means. As the sample covers the whole sky we interpret the weighted means as the global shifts of the Gaia DR2 parallaxes with respect to our eclipsing binary sample. Depending on the choice of the SBC relation the shifts vary from -0.094 to -0.025mas. The weighted mean of the zero-point shift from all colors and calibrations used is d{omega}=-0.054+/-0.024mas. However, the SBC relations based on (B-K) and (V-K) colors, which are the least reddening dependent and have the lowest intrinsic dispersions, give a zero-point shift of d{omega}=-0.031+/-0.011mas in full agreement with results obtained by Lindegren+ (2018A&A...616A...2L) and Arenou+ (2018A&A...616A..17A). Our result confirms the global shift of Gaia DR2 parallaxes of d{omega}=-0.029mas reported by the Gaia team, but we do not confirm the larger zero-point shift reported by a number of follow-up papers.
- ID:
- ivo://CDS.VizieR/J/ApJS/190/77
- Title:
- Detailed analysis of cool WDs in the SDSS
- Short Name:
- J/ApJS/190/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical spectroscopy and near-infrared photometry of 126 cool white dwarfs (WDs) in the Sloan Digital Sky Survey (SDSS DR3). Our sample includes high proper motion targets selected using the SDSS and USNO-B astrometry and a dozen previously known ultracool WD candidates. Our optical spectroscopic observations demonstrate that a clean selection of large samples of cool WDs in the SDSS (and the SkyMapper, Pan-STARRS, and the Large Synoptic Survey Telescope data sets) is possible using a reduced proper motion diagram and a tangential velocity cut-off (depending on the proper motion accuracy) of 30km/s. Our near-infrared observations reveal eight new stars with significant absorption. We use the optical and near-infrared photometry to perform a detailed model atmosphere analysis. More than 80% of the stars in our sample are consistent with either pure hydrogen or pure helium atmospheres. However, the eight stars with significant infrared absorption and the majority of the previously known ultracool WD candidates are best explained with mixed hydrogen and helium atmosphere models. The age distribution of our sample is consistent with a Galactic disk age of 8Gyr. A few ultracool WDs may be as old as 12-13Gyr, but our models have problems matching the spectral energy distributions of these objects. There are only two halo WD candidates in our sample. However, trigonometric parallax observations are required for accurate mass and age determinations and to confirm their membership in the halo.
- 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/A+A/536/L9
- Title:
- Detections of transit variations in KOI 806
- Short Name:
- J/A+A/536/L9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the detection of transit timing variations (TTVs) well in excess of one hour in the Kepler multi-planet candidate system KOI 806. This system exhibits transits consistent with three separate planets - a Super-Earth, a Jupiter, and a Saturn - lying very nearly in a 1:2:5 resonance, respectively.
