- ID:
- ivo://CDS.VizieR/J/ApJS/224/4
- Title:
- GOSSS III. 142 additional O-type systems
- Short Name:
- J/ApJS/224/4
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the third installment of the Galactic O-Star Spectroscopic Survey (GOSSS), a massive spectroscopic survey of Galactic O stars, based on new homogeneous, high signal-to-noise ratio, R~2500 digital observations selected from the Galactic O-Star Catalog. In this paper, we present 142 additional stellar systems with O stars from both hemispheres, bringing the total of O-type systems published within the project to 590. Among the new objects, there are 20 new O stars. We also identify 11 new double-lined spectroscopic binaries, 6 of which are of O+O type and 5 of O+B type, and an additional new tripled-lined spectroscopic binary of O+O+B type. We also revise some of the previous GOSSS classifications, present some egregious examples of stars erroneously classified as O-type in the past, introduce the use of luminosity class IV at spectral types O4-O5.5, and adapt the classification scheme to the work of Arias et al.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/801/91
- Title:
- Gould's Belt Very Large Array survey. IV. Taurus
- Short Name:
- J/ApJ/801/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multi-epoch radio study of the Taurus-Auriga star-forming complex made with the Karl G. Jansky Very Large Array at frequencies of 4.5GHz and 7.5GHz. We detect a total of 610 sources, 59 of which are related to young stellar objects (YSOs) and 18 to field stars. The properties of 56% of the young stars are compatible with non-thermal radio emission. We also show that the radio emission of more evolved YSOs tends to be more non-thermal in origin and, in general, that their radio properties are compatible with those found in other star-forming regions. By comparing our results with previously reported X-ray observations, we notice that YSOs in Taurus-Auriga follow a Gudel-Benz relation with {kappa}=0.03, as we previously suggested for other regions of star formation. In general, YSOs in Taurus-Auriga and in all the previous studied regions seem to follow this relation with a dispersion of ~1dex. Finally, we propose that most of the remaining sources are related with extragalactic objects but provide a list of 46 unidentified radio sources whose radio properties are compatible with a YSO nature.
- ID:
- ivo://CDS.VizieR/J/ApJS/81/5
- Title:
- Green Bank neutral hydrogen survey
- Short Name:
- J/ApJS/81/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Neutral hydrogen observations at 21cm, made at the Green Bank 91m telescope in 1984, 1985 and 1986, of a large sample of dwarf and other low surface brightness galaxies are presented. The majority of galaxies classified in the Uppsala General Catalogue as dwarf, irregular, Sdm, or later and with declinations north of the range of the Arecibo telescope ({delta}>38{deg}) have been observed, along with a number of galaxies farther south for flux comparisons with Arecibo observations (Schneider et al., 1990ApJS...72..245S, Paper I), totaling over 600 galaxies. About half of these galaxies have no previously published detections. In total, counting previous detections, over 80% of these late-type systems are detected at Green Bank. We have examined the galaxies for potential confusion with nearby galaxies, and we also present substantially better signal-to-noise measurements for many previously detected galaxies. Some general results of the Green Bank survey are discussed here, but the total data base of northern dwarf and low surface brightness galaxies, including new measurements of the galaxies' photographic magnitudes, will be examined in subsequent papers.
- ID:
- ivo://CDS.VizieR/J/ApJ/812/114
- Title:
- Grism Lens-Amplified Survey from Space (GLASS). I.
- Short Name:
- J/ApJ/812/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We give an overview of the Grism Lens Amplified Survey from Space (GLASS), a large Hubble Space Telescope program aimed at obtaining grism spectroscopy of the fields of 10 massive clusters of galaxies at redshift z=0.308-0.686, including the Hubble Frontier Fields (HFF). The Wide Field Camera 3 (WFC3) yields near-infrared spectra of the cluster cores covering the wavelength range 0.81-1.69{mu}m through grisms G102 and G141, while the Advanced Camera for Surveys in parallel mode provides G800L spectra of the infall regions of the clusters. The WFC3 spectra are taken at two almost orthogonal position angles in order to minimize the effects of confusion. After summarizing the scientific drivers of GLASS, we describe the sample selection as well as the observing strategy and data processing pipeline. We then utilize MACS J0717.5+3745, a HFF cluster and the first one observed by GLASS, to illustrate the data quality and the high-level data products. Each spectrum brighter than H_AB_=23 is visually inspected by at least two co-authors and a redshift is measured when sufficient information is present in the spectra. Furthermore, we conducted a thorough search for emission lines through all of the GLASS WFC3 spectra with the aim of measuring redshifts for sources with continuum fainter than H_AB_=23. We provide a catalog of 139 emission-line-based spectroscopic redshifts for extragalactic sources, including three new redshifts of multiple image systems (one probable, two tentative).
- ID:
- ivo://CDS.VizieR/J/A+A/598/A26
- Title:
- HADES RV Programme with HARPS-N at TNG. II.
- Short Name:
- J/A+A/598/A26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The distribution of exoplanets around low-mass stars is still not well understood. Such stars, however, present an excellent opportunity for reaching down to the rocky and habitable planet domains. The number of current detections used for statistical purposes remains relatively modest and different surveys, using both photometry and precise radial velocities, are searching for planets around M dwarfs. Our HARPS-N red dwarf exoplanet survey is aimed at the detection of new planets around a sample of 78 selected stars, together with the subsequent characterization of their activity properties. Here we investigate the survey performance and strategy. From 2700 observed spectra, we compare the radial velocity determinations of the HARPS-N DRS pipeline and the HARPS-TERRA code, calculate the mean activity jitter level, evaluate the planet detection expectations, and address the general question of how to define the strategy of spectroscopic surveys in order to be most efficient in the detection of planets. We find that the HARPS-TERRA radial velocities show less scatter and we calculate a mean activity jitter of 2.3m/s for our sample. For a general radial velocity survey with limited observing time, the number of observations per star is key for the detection efficiency. In the case of an early M-type target sample, we conclude that approximately 50 observations per star with exposure times of 900s and precisions of approximately 1m/s maximizes the number of planet detections.
- ID:
- ivo://CDS.VizieR/J/other/NatAs/4.1072
- Title:
- HaloSat survey of southern Galactic halo
- Short Name:
- J/other/NatAs/4.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Milky Way galaxy is surrounded by a circumgalactic medium (CGM) that may play a key role in galaxy evolution as the source of gas for star formation and a repository of metals and energy produced by star formation and nuclear activity. The CGM may also be a repository for baryons seen in the early universe, but undetected locally. The CGM has an ionized component at temperatures near 2x10^6^K studied primarily in the soft X-ray band. Here we report a survey of the southern Galactic sky with a soft X-ray spectrometer optimized to study diffuse soft X-ray emission. The X-ray emission is best fit with a disc-like model based on the radial profile of the surface density of molecular hydrogen, a tracer of star formation, suggesting that the X-ray emission is predominantly from hot plasma produced via stellar feedback. Strong variations in the X-ray emission on angular scales of ~10 degrees indicate that the CGM is clumpy. Addition of an extended, and possibly massive, halo component is needed to match the halo density inferred from other observations.
- ID:
- ivo://CDS.VizieR/J/ApJS/178/247
- Title:
- H{alpha} and [NII] survey in local 11 Mpc
- Short Name:
- J/ApJS/178/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of a broader effort to characterize the population of star-forming galaxies in the local universe, we have carried out an H{alpha}+[NII] imaging survey for an essentially volume-limited sample of galaxies within 11Mpc of the Milky Way. This first paper describes the design of the survey, the observation, data processing, and calibration procedures, and the characteristics of the galaxy sample. The main product of the paper is a catalog of integrated H{alpha} fluxes, luminosities, and equivalent widths for the galaxies in the sample. We briefly discuss the completeness properties of the survey and compare the distribution of the sample and its star formation properties to other large H{alpha} imaging surveys. These data form the foundation for a series of follow-up studies of the star formation properties of the local volume, and the properties and duty cycles of star formation bursts in dwarf galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/706/599
- Title:
- H{alpha} and UV SFR in the local volume
- Short Name:
- J/ApJ/706/599
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a complete sample of ~300 star-forming galaxies within 11Mpc of the Milky Way, we evaluate the consistency between star formation rates (SFRs) inferred from the far ultraviolet (FUV) non-ionizing continuum and H{alpha} nebular emission, assuming standard conversion recipes in which the SFR scales linearly with luminosity at a given wavelength. Our analysis probes SFRs over 5 orders of magnitude, down to ultra-low activities on the order of ~10^-4^M_{sun}_/yr. The data are drawn from the 11Mpc H{alpha} and Ultraviolet Galaxy Survey (11HUGS), which has obtained H{alpha} fluxes from ground-based narrowband imaging, and UV fluxes from imaging with GALEX.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/2041
- Title:
- H{alpha} emitters at z=2.23
- Short Name:
- J/MNRAS/416/2041
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a narrow-band (H_2_S1, {lambda}_c_=2.121um, {delta}{lambda}=0.021um) imaging search with Wide Field Camera/United Kingdom Infrared Telescope for H{alpha} emitters (HAEs) around several potential signposts of rare (~10^-7^-10^-8^ comoving Mpc^-3^) overdense regions at z=2.23: an overdensity of quasi-stellar objects [QSOs; 2dF QSO Redshift Survey (2QZ) cluster], a powerful, high-redshift radio galaxy (HzRG) and a concentration of submillimetre galaxies (SMGs) and optically faint radio galaxies (OFRGs). In total, we detect 137 narrow-band emitter candidates down to emission-line fluxes of 0.5-1x10^-16^erg/s/cm^2^, across a total area of 0.56deg^2^ (2.1x10^5^ comoving Mpc^3^ at z=2.23) in these fields.
- ID:
- ivo://CDS.VizieR/J/ApJS/208/28
- Title:
- H{alpha} survey in the ONC
- Short Name:
- J/ApJS/208/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from an H{alpha} emission line survey in a 1 deg^2^ area centered on the Orion Nebula Cluster, obtained with the Wide Field Grism Spectrograph 2 on the 2.2 m telescope of the University of Hawaii. We identified 587 stars with H{alpha} emission, 99 of which, located mainly in the outer regions of the observed area, have not appeared in previous H{alpha} surveys. We determined the equivalent width (EW) of the line and, based on this, classified 372 stars as classical T Tauri stars (CTTSs) and 187 as weak-line T Tauri stars (WTTSs). Simultaneous r', i' photometry indicates a limiting magnitude of r' ~ 20 mag, but the sample is incomplete at r' > 17 mag. The surface distribution of the H{alpha} emission stars reveals a clustered population and a dispersed population, the former consisting of younger and more massive young stars than the latter. Comparison of the derived EWs with those found in the literature indicates variability of the H{alpha} line. We found that the typical amplitudes of the variability are not greater than a factor of two to three in most cases. We identified a subgroup of low-EW stars with infrared signatures indicative of optically thick accretion disks. We studied the correlations between the EW and other properties of the stars. Based on literature data, we examined several properties of our CTTS and WTTS subsamples and found significant differences in mid-infrared color indices, average rotational periods, and spectral energy distribution characteristics of the subsamples.
