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- ID:
- ivo://CDS.VizieR/J/ApJ/709/377
- Title:
- The globular cluster system of NGC 4636
- Short Name:
- J/ApJ/709/377
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic study of the globular clusters (GCs) in the giant elliptical galaxy NGC 4636 in the Virgo Cluster. We selected target GC candidates using the Washington photometry derived from the deep CCD images taken at the KPNO 4m Telescope. Then we obtained the spectra of 164 target objects in the field of NGC 4636 using the Multi-Object Spectroscopy mode of Faint Object Camera and Spectrograph on the Subaru 8.2m Telescope. We have measured the velocities for 122 objects: 105 GCs in NGC 4636, the nucleus of NGC 4636, 11 foreground stars, two background galaxies, and three probable intracluster GCs in the Virgo Cluster. The GCs in NGC 4636 are located in the projected galactocentric radius within 10' (corresponding to 43kpc). The measured velocities for the GCs range from ~300km/s to ~1600km/s, with a mean value of 932^+25^_-22_km/s, which is in good agreement with the velocity for the nucleus of NGC 4636, 928+/-45km/s.
- ID:
- ivo://CDS.VizieR/J/ApJ/797/31
- Title:
- The G+M eclipsing binary V530 Orionis photometry
- Short Name:
- J/ApJ/797/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report extensive photometric and spectroscopic observations of the 6.1 day period, G+M-type detached double-lined eclipsing binary V530 Ori, an important new benchmark system for testing stellar evolution models for low-mass stars. We determine accurate masses and radii for the components with errors of 0.7% and 1.3%, as follows: M_A_=1.0038+/-0.0066 M_{sun}_, M_B_=0.5955+/-0.0022 M_{sun}_, R_A_=0.980+/-0.013 R_{sun}_, and R_B_=0.5873+/-0.0067 R_{sun}_. The effective temperatures are 5890+/-100 K (G1 V) and 3880+/-120 K (M1 V), respectively. A detailed chemical analysis probing more than 20 elements in the primary spectrum shows the system to have a slightly subsolar abundance, with [Fe/H]=-0.12+/-0.08. A comparison with theory reveals that standard models underpredict the radius and overpredict the temperature of the secondary, as has been found previously for other M dwarfs. On the other hand, models from the Dartmouth series incorporating magnetic fields are able to match the observations of the secondary star at the same age as the primary (~3 Gyr) with a surface field strength of 2.1+/-0.4 kG when using a rotational dynamo prescription, or 1.3+/-0.4 kG with a turbulent dynamo approach, not far from our empirical estimate for this star of 0.83+/-0.65 kG. The observations are most consistent with magnetic fields playing only a small role in changing the global properties of the primary. The V530 Ori system thus provides an important demonstration that recent advances in modeling appear to be on the right track to explain the long-standing problem of radius inflation and temperature suppression in low-mass stars.
6704. The GSH Binary Survey
- ID:
- ivo://CDS.VizieR/J/AN/338/61
- Title:
- The GSH Binary Survey
- Short Name:
- J/AN/338/61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Since 2009 the Grossschwabhausen binary survey is carried out at the University Observatory Jena. This new imaging survey uses available time slots during photometric monitoring campaigns, caused by non-photometric weather conditions, which often exhibit a good atmospheric seeing. The goal of the project is to obtain current relative astrometric measurements of binary systems, that are listed in the Washington Visual Double Star Catalog. In this paper we characterize the target sample of the survey, describe the imaging observations, the astrometric measurements including the astrometric calibration, and present relative astrometric measures of all binaries, which could be obtained in the course of the survey, so far.
- ID:
- ivo://CDS.VizieR/J/A+A/397/463
- Title:
- The Hamburg/SAO Survey for BCGs. I.
- Short Name:
- J/A+A/397/463
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the description and the first results of a new project devoted to the search for extremely metal-deficient blue compact/HII-galaxies (BCGs) and to the creation of a well selected large BCG sample with strong emission lines. Such galaxies should be suitable for reliable determination of their oxygen abundance through the measurement of the faint [OIII]4363{AA} line. The goals of the project are two-fold: a) to discover a significant number of new extremely metal-poor galaxies (Z<=1/20Z_{sun}_), and b) to study the metallicity distribution of local BCGs. Selection of candidates for follow-up slit spectroscopy is performed on the database of objective prism spectra of the Hamburg Quasar Survey. The sky region is limited by {delta}>=0{deg} and b^II^<=-30{deg}. In this paper we present the results of the follow-up spectroscopy conducted with the Russian 6m telescope. The list of observed candidates contained 52 objects, of which 46 were confirmed as strong-lined BCGs (EW([OIII]5007>=100{AA}). The remaining five lower excitation ELGs include three BCGs, and two galaxies classified as SBN (Starburst Nucleus) and DANS (Dwarf Amorphous Nucleus Starburst). One object is identified as a quasar with a strong Ly_alpha emission line near {lambda}=5000{AA} (z~3). We provide a list with coordinates, measured radial velocities, B-magnitudes, equivalent widths EW([OIII]5007) and EW(H{beta}) and for the 46 strong-lined BCGs the derived oxygen abundances 12+log(O/H). The abundances range between 7.42 and 8.4 (corresponding to metallicities between 1/30 and 1/3Z_{sun}_). The sample contains four galaxies with Z<=1/20Z_{sun}_, of which three are new discoveries. This demonstrates the high efficiency of the new project to find extremely metal-deficient galaxies. The radial velocities of the strong-lined ELGs range between 500 and 19000km/s with a median value of ~6400km/s. The typical B-magnitudes of the galaxies presented are 17.0mag-18.0mag.
- ID:
- ivo://CDS.VizieR/J/AJ/127/180
- Title:
- The Hawaii Hubble Deep Field North
- Short Name:
- J/AJ/127/180
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a deep multicolor imaging survey of 0.2deg^2^ centered on the Hubble Deep Field North (HDF-N). We shall refer to this region as the Hawaii HDF-N. Deep data were collected in U, B, V, R, I, and z' bands over the central 0.2deg^2^ and in HK' over a smaller region covering the Chandra Deep Field North. The data were reduced to have accurate relative photometry and astrometry across the entire field to facilitate photometric redshifts and spectroscopic follow-up. We have compiled a catalog of 48858 objects in the central 0.2deg^2^ detected at 5{sigma} significance in a 3" aperture in either R or z' band. Number counts and color-magnitude diagrams are presented and shown to be consistent with previous observations. Using color selection we have measured the density of objects at 3<z<7. Our multicolor data indicates that samples selected at z>5.5 using the Lyman break technique suffer from more contamination by low-redshift objects than suggested by previous studies.
- ID:
- ivo://CDS.VizieR/J/ApJS/94/461
- Title:
- The Hawai K-band survey. III.
- Short Name:
- J/ApJS/94/461
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectra and multicolor (B,I,K) data for near-infrared (K) selected spatially complete magnitude limited (K<20) galaxy samples from the Hawaii Survey. The redshift identification of the sample of 298 galaxies is substantially complete to a B magnitude of 26 and an I magnitude of 22.5, and identification of observed galaxies ranges from nearly 100% completeness at K<18 to ~70% completeness at K=19-20. We note that many of the unidentified objects appear to be red (I-K) objects which are flat in the optical and spectroscopically featureless. Strengths of spectral-line features and breaks are tabulated for the 262 galaxies with reasonably secure redshifts. The measured redshifts nearly all fall at z<1, with the exception of a compact absorption-line object at z=2.35. At K>=18, the redshift distribution is well fitted by a model with no luminosity evolution, implying that from the K-band Hubble diagram, the Hubble constant can vary at most by 10% over the redshift range from z~0.025 to 0.25, and that positive luminosity evolution at any significant level between z=0 and z=1 is ruled out. However, the evolution of both the emission-line strengths and the 4000{AA} break indicates that galaxies were undergoing significantly more star formation at z=1 than at the present time.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A11
- Title:
- The Hawk-I UDS and GOODS Survey (HUGS)
- Short Name:
- J/A+A/570/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a new, ultra-deep, near-infrared imaging survey executed with the Hawk-I imager at the ESO VLT, of which we make all the data (images and catalog) public. This survey, named HUGS (Hawk-I UDS and GOODS Survey), provides deep, high-quality imaging in the K and Y bands over the portions of the UKIDSS UDS and GOODS-South fields covered by the CANDELS HST WFC3/IR survey. In this paper we describe the survey strategy, the observational campaign, the data reduction process, and the data quality. We show that, thanks to exquisite image quality and extremely long exposure times, HUGS delivers the deepest K-band images ever collected over areas of cosmological interest, and in general ideally complements the CANDELS data set in terms of image quality and depth. In the GOODS-S field, the K-band observations cover the whole CANDELS area with a complex geometry made of 6 different, partly overlapping pointings, in order to best match the deep and wide areas of CANDELS imaging. In the deepest region (which includes most of the Hubble Ultra Deep Field) exposure times exceed 80 hours of integration, yielding a 1-{sigma} magnitude limit per square arcsec of ~=28.0ABmag. The seeing is exceptional and homogeneous across the various pointings, confined to the range 0.38-0.43arcsec. In the UDS field the survey is about one magnitude shallower (to match the correspondingly shallower depth of the CANDELS images) but includes also Y-band band imaging (which, in the UDS, was not provided by the CANDELS WFC3/IR imaging). In the K-band, with an average exposure time of 13 hours, and seeing in the range 0.37-0.43arcsec, the 1-{sigma} limit per square arcsec in the UDS imaging is ~=27.3ABmag. In the Y-band, with an average exposure time ~=8h, and seeing in the range 0.45-0.5arcsec, the imaging yields a 1-{sigma} limit per square arcsec of ~=28.3ABmag. We show that the HUGS observations are well matched to the depth of the CANDELS WFC3/IR data, since the majority of even the faintest galaxies detected in the CANDELS H-band images are also detected in HUGS. Finally we present the K-band galaxy number counts produced by combining the HUGS data from the two fields. We show that the slope of the number counts depends sensitively on the assumed distribution of galaxy sizes, with potential impact on the estimated extra-galactic background light.
- ID:
- ivo://CDS.VizieR/J/ApJS/224/5
- Title:
- The Herschel Orion Protostar Survey (HOPS): SEDs
- Short Name:
- J/ApJS/224/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present key results from the Herschel Orion Protostar Survey (HOPS): spectral energy distributions (SEDs) and model fits of 330 young stellar objects, predominantly protostars, in the Orion molecular clouds. This is the largest sample of protostars studied in a single, nearby star formation complex. With near-infrared photometry from 2MASS, mid- and far-infrared data from Spitzer and Herschel, and submillimeter photometry from APEX, our SEDs cover 1.2-870{mu}m and sample the peak of the protostellar envelope emission at ~100{mu}m. Using mid-IR spectral indices and bolometric temperatures, we classify our sample into 92 Class 0 protostars, 125 Class I protostars, 102 flat-spectrum sources, and 11 Class II pre-main-sequence stars. We implement a simple protostellar model (including a disk in an infalling envelope with outflow cavities) to generate a grid of 30400 model SEDs and use it to determine the best-fit model parameters for each protostar. We argue that far-IR data are essential for accurate constraints on protostellar envelope properties. We find that most protostars, and in particular the flat-spectrum sources, are well fit. The median envelope density and median inclination angle decrease from Class 0 to Class I to flat-spectrum protostars, despite the broad range in best-fit parameters in each of the three categories. We also discuss degeneracies in our model parameters. Our results confirm that the different protostellar classes generally correspond to an evolutionary sequence with a decreasing envelope infall rate, but the inclination angle also plays a role in the appearance, and thus interpretation, of the SEDs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/419/3505
- Title:
- The HeViCS Bright Galaxy Sample
- Short Name:
- J/MNRAS/419/3505
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the Herschel Virgo Cluster Survey and the first data that cover the complete survey area (four 4x4deg^2^ regions). We use these data to measure and compare the global far-infrared properties of 78 optically bright galaxies that are selected at 500um and detected in all five far-infrared bands. We show that our measurements and calibration are broadly consistent with previous data obtained by the IRAS, ISO, Spitzer and Planck. We use SPIRE and PACS photometry data to produce 100-, 160-, 250-, 350- and 500-um cluster luminosity distributions.
