- ID:
- ivo://CDS.VizieR/J/ApJS/225/27
- Title:
- 3D-HST Survey: grism spectra master catalog
- Short Name:
- J/ApJS/225/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present reduced data and data products from the 3D-HST survey, a 248-orbit HST Treasury program. The survey obtained WFC3 G141 grism spectroscopy in four of the five CANDELS fields: AEGIS, COSMOS, GOODS-S, and UDS, along with WFC3 H_140_ imaging, parallel ACS G800L spectroscopy, and parallel I_814_ imaging. In a previous paper, we presented photometric catalogs in these four fields and in GOODS-N, the fifth CANDELS field. Here we describe and present the WFC3 G141 spectroscopic data, again augmented with data from GO-1600 in GOODS-N (PI: B. Weiner). We developed software to automatically and optimally extract interlaced two-dimensional (2D) and one-dimensional (1D) spectra for all objects in the Skelton+ (2014, J/ApJS/214/24) photometric catalogs. The 2D spectra and the multi-band photometry were fit simultaneously to determine redshifts and emission line strengths, taking the morphology of the galaxies explicitly into account. The resulting catalog has redshifts and line strengths (where available) for 22548 unique objects down to JH_IR_<=24 (79609 unique objects down to JH_IR<=26). Of these, 5459 galaxies are at z>1.5 and 9621 are at 0.7<z<1.5, where H{alpha} falls in the G141 wavelength coverage. The typical redshift error for JH_IR_<=24 galaxies is {sigma}_z_~0.003x(1+z), i.e., one native WFC3 pixel. The 3{sigma} limit for emission line fluxes of point sources is 2.1x10^-17^erg/s/cm^2^.
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- ID:
- ivo://CDS.VizieR/J/A+A/642/A56
- Title:
- Diagnostic for accretion/outflow in NGC 2264
- Short Name:
- J/A+A/642/A56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 2264 is a young cluster whose accretion properties can be investigated in detail by taking advantage of the FLAMES data in the context of the Gaia-ESO Survey. In fact, the analysis of the H{alpha} emission line profile can provide us with information about the accretion and ejection activity of young stars. However, a strong nebular emission that contributes to the H{alpha} emission can alter the profiles, with consequences for their physical interpretation. Our study is aimed at investigating the accretion and ejection properties of NGC 2264 by applying a proper treatment of the sky contribution to the H{alpha} and forbidden emission lines (FELs; [SII] and [NII] doublets). We developed a tool, the OH{alpha}NA-method, to handle the strong nebular contribution and spectra with spurious profiles of the H{alpha} and FELs, namely altered H{alpha} profiles or absorption features artificially created where emission lines (FELs) are expected. We derived the quantitative measurements of relevant parameters to describe the accretion and ejection processes in young members of NGC 2264, focusing on reliable quantities derived from the width of the lines, which is relatively unaffected by the nebular emission, unlike the intensity peak, which can be altered significantly. We derive the quantitative measurements related to the H{alpha} emission line and discuss the comparison between the original and sky-subtracted spectra. We thus reveal possible profile alterations with consequences for their physical interpretation. Furthermore, we show the analysis of the variability for multi-epoch observations, also deriving the velocity of the infalling and outflowing plasma from the wings of the broad H{alpha} emission line (in accreting stars). We also explore the mass accretion rate versus full width at zero intensity of the H{alpha} line, namely dM/dt versus FWZI(H{alpha}), a correlation based on the width of the emission line, which is expected to be more robust with respect to any measurement derived from the peak (e.g., H{alpha}_10%_) and possibly altered by the nebular contribution. We are able to ascertain that more than 20% of the confirmed accretors, which have already been identified in NGC 2264, are affected by the alteration of their line profiles due to the contribution of the nebular emission. Therefore, this is an important issue to consider when investigating accretion and ejection processes in young stellar clusters. While a small fraction of spectra can be unequivocally classified as either unaffected by nebular emission or dominated by nebular emission, the majority (>90%) represent intermediate cases whose spectral features have to be investigated in detail to derive reliable measurements of the relevant parameters and their physical implications.
- ID:
- ivo://CDS.VizieR/J/AN/316/39
- Title:
- Diameter-limited Northern sky galaxies catalog
- Short Name:
- J/AN/316/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In order to understand if the differences between the SSRS of Da Costa et al. (1988ApJ...327..544D) (which is diameter limited) and the CfA survey (Huchra et al., 1995, Cat. <VII/193>) (which is magnitude limited) are real or induced by the different selection criteria, the CfA survey has been directly compared with a diameter-limited sample covering the same region of the sky (UDLS, Bardelli et al., 1991A&A...248..354B, Zucca et al., 1991MNRAS.253..401Z). In this paper we present the data for the galaxies in the UDLS sample, in an updated version which collects velocity information from the literature until June 1993, leaving us with a velocity completeness better than ~95%.
- ID:
- ivo://CDS.VizieR/J/ApJ/746/101
- Title:
- Diameters and temperatures of AFG stars
- Short Name:
- J/ApJ/746/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have executed a survey of nearby, main-sequence A-, F-, and G-type stars with the CHARA Array, successfully measuring the angular diameters of forty-four stars with an average precision of ~1.5%. We present new measures of the bolometric flux, which in turn leads to an empirical determination of the effective temperature for the stars observed. In addition, these CHARA-determined temperatures, radii, and luminosities are fit to Yonsei-Yale model isochrones to constrain the masses and ages of the stars. These results are compared to indirect estimates of these quantities obtained by collecting photometry of the stars and applying them to model atmospheres and evolutionary isochrones. We find that for most cases, the models overestimate the effective temperature by ~1.5%-4% when compared to our directly measured values. The overestimated temperatures and underestimated radii in these works appear to cause an additional offset in the star's surface gravity measurements, which consequently yield higher masses and younger ages, in particular for stars with masses greater than ~1.3 M_{sun}_. Additionally, we compare our measurements to a large sample of eclipsing binary stars, and excellent agreement is seen within both data sets. Finally, we present temperature relations with respect to (B-V) and (V-K) colors as well as spectral type, showing that calibration of effective temperatures with errors ~1% is now possible from interferometric angular diameters of stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/680/728
- Title:
- Diameters of exoplanet host stars
- Short Name:
- J/ApJ/680/728
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured the angular diameters for a sample of 24 exoplanet host stars using Georgia State University's CHARA Array interferometer. We use these improved angular diameters together with Hipparcos parallax measurements to derive linear radii and to estimate the stars' evolutionary states.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1559
- Title:
- Diameters of Galactic open star clusters
- Short Name:
- J/AJ/131/1559
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present paper presents a tabulation of data on all 600 Galactic open clusters for which it is currently possible to calculate linear diameters. As expected, the youngest "clusters", with ages <15Myr, contain a significant (>=20%) admixture of associations. Among intermediate-age clusters, with ages in the range 15Myr to 1.5Gyr, the median cluster diameter is found to increase with age. Small, compact clusters are rare among objects with ages >1.5Gyr. Open clusters with ages >1Gyr appear to form what might be termed a "cluster thick disk", part of which consists of objects that were probably captured gravitationally by the main body of the Galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/620/961
- Title:
- Diameters of Mira stars in JHK' bands
- Short Name:
- J/ApJ/620/961
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first spatially resolved observations of a sample of 23 Mira stars simultaneously measured in the near-infrared J, H, and K' bands. The technique used was optical long-baseline interferometry, and we present for each star visibility amplitude measurements as a function of wavelength. We also present characteristic sizes at each spectral band, obtained by fitting the measured visibilities to a simple uniform disk model. This approach reveals the general relation J diameter < H diameter < K' diameter.
- ID:
- ivo://CDS.VizieR/J/AcA/52/129
- Title:
- DIA OGLE2 candidate variable stars catalog
- Short Name:
- J/AcA/52/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first edition of a catalog of variable stars from OGLE-II Galactic bulge data covering 3 years: 1997-1999. Typically 200-300 I band data points are available in 49 fields between -11 and +11 degrees in galactic longitude, totaling roughly 11 square degrees in sky coverage. Photometry was obtained using the Difference Image Analysis (DIA) software and tied to the OGLE data base with the DoPhot package. The present version of the catalog comprises 221801 light curves. In this preliminary work the level of contamination by spurious detections is still about 10%. Parts of the catalog have only crude calibration, insufficient for distance determinations. The next, fully calibrated, edition will include the data collected in year 2000. The data is accessible via ftp, at ftp://bulge.princeton.edu/ogle/ogle2/bulge_dia_variables
- ID:
- ivo://CDS.VizieR/J/A+A/376/356
- Title:
- Diatomic molecules collisional rates
- Short Name:
- J/A+A/376/356
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A number of diatomic molecules have been found in vibrationally excited states in several cosmic objects. The molecules in vibrationally excited states provide valuable information about the physical conditions prevailing near star forming regions and in circumstellar envelopes of late-type stars. To analyze the spectrum of such molecules, some of the important parameters required are the collisional rate coefficients for vib-rotational transitions in the molecule. Currently, knowledge of collisional rate coefficients is very poor. Here, we discuss a method for calculating the collisional rate coefficients for vib-rotational transitions in a diatomic molecule, where the colliding partner H_2_ is considered as a structureless particle. This method is quite good for high temperatures (usually found in star-forming regions and in circumstellar envelopes of late-type stars), but may be questioned for low temperatures. As an example, calculations for the CS molecule at 500K for three vibrational states are presented.
- ID:
- ivo://CDS.VizieR/J/A+A/591/A20
- Title:
- DIB and NaD spectra of 3 nearby stars
- Short Name:
- J/A+A/591/A20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Diffuse interstellar absorption bands (DIBs) of largely unknown chemical origin are regularly observed primarily in distant early-type stars. More recently, detections in nearby late-type stars have also been claimed. These stars' spectra are dominated by stellar absorption lines. Specifically, strong interstellar atomic and DIB absorption has been reported in tau Boo. We test these claims by studying the strength of interstellar absorption in high-resolution TIGRE spectra of the nearby stars tau Boo, HD 33608, and alpha CrB. We focus our analysis on a strong DIB located at 5780.61{AA} and on the absorption of interstellar Na. First, we carry out a differential analysis by comparing the spectra of the highly similar F-stars, tau Boo and HD 33608, whose light, however, samples different lines of sight. To obtain absolute values for the DIB absorption, we compare the observed spectra of tau Boo, HD 33608, and alpha CrB to PHOENIX models and carry out basic spectral modeling based on Voigt line profiles.