- ID:
- ivo://CDS.VizieR/J/ApJS/165/256
- Title:
- Fluorescent H_2_ emission from T Tauri stars
- Short Name:
- J/ApJS/165/256
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We survey fluorescent H2 emission in HST STIS spectra of the classical T Tauri stars (CTTSs) TW Hya, DF Tau, RU Lupi, T Tau, and DG Tau, and the weak-lined T Tauri star (WTTS) V836 Tau. From each of those sources we detect between 41 and 209 narrow H_2_ emission lines, most of which are pumped by strong Ly{alpha} emission. H_2_ emission is not detected from the WTTS V410 Tau. The fluorescent H_2_ emission appears to be common to circumstellar environments around all CTTSs, but high spectral and spatial resolution STIS observations reveal diverse phenomenon.
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- ID:
- ivo://CDS.VizieR/J/A+A/566/A1
- Title:
- Flux- and volume-limited groups for SDSS galaxies
- Short Name:
- J/A+A/566/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We provide flux-limited and volume-limited galaxy group and cluster catalogues, based on the spectroscopic sample of the SDSS data release 10 galaxies. We used a modified friends-of-friends (FoF) method with a variable linking length in the transverse and radial directions to identify as many realistic groups as possible. The flux-limited catalogue incorporates galaxies down to m_r_=17.77mag. It includes 588193 galaxies and 82458 groups. The volume-limited catalogues are complete for absolute magnitudes down to M_r_= -18.0, -18.5, -19.0, -19.5, -20.0, -20.5, and -21.0; the completeness is achieved within different spatial volumes, respectively. Our analysis shows that flux-limited and volume-limited group samples are well compatible to each other, especially for the larger groups/clusters. Dynamical mass estimates, based on radial velocity dispersions and group extent in the sky, are added to the extracted groups. The catalogues can also be accessed via http://cosmodb.to.ee.
- ID:
- ivo://CDS.VizieR/J/ApJ/723/1469
- Title:
- Flux calibrations and WZ Oph photometry
- Short Name:
- J/ApJ/723/1469
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Among several EB distance algorithms, direct comparison of observed and theoretical fluxes is particularly straightforward, although it requires absolute flux calibrations for which only a modest number of publications exist. Here, we measure UBV RI and uvby flux calibrations and calibration ratios from astronomical objects in ways not previously tried, specifically for EBs, single stars within 80pc, and the Sun. All of the single stars are below about 6500K temperature. Interstellar extinction is avoided by a restriction to nearby targets. Some photometric band calibrations in the literature are accurate enough for very good EB distance determinations if star temperatures are accurately known, especially considering that estimated distance has only a square-root dependence on calibration constant, but accurate band-to-band calibration ratios are keys to the combined temperature-distance problem. Band-independent canceling factors (star radii and distances) allow calibration ratio measurement with enhanced accuracy, compared to individual band calibrations. A physical EB model with embedded stellar atmosphere emission optimally matches theory to observations for the binaries. Single star candidates are identified as reliably single if their radial velocity variations are below 100m/s. For the most part, we find good agreement with some of the previous calibrations and the ratios are improved.
- ID:
- ivo://CDS.VizieR/J/AJ/152/102
- Title:
- Flux conversion factors for the Swift/UVOT filters
- Short Name:
- J/AJ/152/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss the transformation of observed photometry into flux for the creation of spectral energy distributions (SED) and the computation of bolometric luminosities. We do this in the context of supernova studies, particularly as observed with the Swift spacecraft, but the concepts and techniques should be applicable to many other types of sources and wavelength regimes. Traditional methods of converting observed magnitudes to flux densities are not very accurate when applied to UV photometry. Common methods for extinction and the integration of pseudo-bolometric fluxes can also lead to inaccurate results. The sources of inaccuracy, though, also apply to other wavelengths. Because of the complicated nature of translating broadband photometry into monochromatic flux densities, comparison between observed photometry and a spectroscopic model is best done by forward modeling the spectrum into the count rates or magnitudes of the observations. We recommend that integrated flux measurements be made using a spectrum or SED which is consistent with the multi-band photometry rather than converting individual photometric measurements to flux densities, linearly interpolating between the points, and integrating. We also highlight some specific areas where the UV flux can be mischaracterized.
- ID:
- ivo://CDS.VizieR/J/AJ/74/366
- Title:
- Flux densities at 22.25 MHz. I.
- Short Name:
- J/AJ/74/366
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Flux densities for 200 radio sources have been derived from observations with the 22.25MHz radio telescope at the Dominion Radio Astrophysical Observatory. Ionospheric conditions, the method of calibration, and the reduction procedure are described. The effects of these new measures on the spectral indices of the sources are indicated. Note: this catalogue is superseded by Cat. <J/A+AS/65/485>
- ID:
- ivo://CDS.VizieR/J/AN/338/700
- Title:
- Flux densities for 290 blazars
- Short Name:
- J/AN/338/700
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of nine years of the blazar observing programme at the RATAN-600 radio telescope (2005-2014). The data were obtained at six frequency bands (1.1, 2.3, 4.8, 7.7, 11.2, 21.7GHz) for 290 blazars, mostly BL Lacs. In addition, we used data at 37GHz obtained quasi-simultaneously with the Metsahovi radio observatory for some sources. For each source NVSS name (RA (hhmmss) and DEC (ddmmss) for the J2000.0 epoch), and flux densities at seven frequencies are presented (1.1-37GHz).
- ID:
- ivo://CDS.VizieR/J/AZh/77/499
- Title:
- Flux densities of 235 pulsars at 102.5MHz
- Short Name:
- J/AZh/77/499
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The flux densities of 235 mostly faint pulsars at 102.5MHz are presented. The observations were carried out on the very sensitive Large Phased Array of the Lebedev Institute of Physics in 1994-1998. The procedure used for the observations and data processing is described in detail, and estimates of probable errors, including the effect of interstellar scintillations, are given. The mean spectral indices at 102-408MHz for normal and millisecond pulsars are calculated and compared with information from higher frequency data. There is a deficit of pulsars at distances of less than 3 kpc.
- ID:
- ivo://CDS.VizieR/J/AZh/83/241
- Title:
- Flux-density-complete sample of radio sources
- Short Name:
- J/AZh/83/241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of observations of flux-density- complete sample of radio with the RATAN-600 radio telescope at 0.97, 2.3, 3.9, 7.7, 11.1, and 21.7GHz. The sample was extracted from the GB6 catalog (<VIII/40>) at 4.85GHz, and contains all the sources at declination zone 74-75{deg} (J2000) with flux densities S(4.85)>100mJy. We have obtained optical identifications for 67% of radio sources with flat spectra and 36% of those with normal spectra.
- ID:
- ivo://CDS.VizieR/J/ApJ/696/729
- Title:
- Fluxes and abundances of PNe in M33
- Short Name:
- J/ApJ/696/729
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The planetary nebula (PN) population of M33 is studied via multifiber spectroscopy with Hectospec at the MMT. In this paper, we present the spectra of 102 PNe, whereas plasma diagnostic and chemical abundances were performed on the 93 PNe where the necessary diagnostic lines were measured. About 20% of the PNe are compatible with being Type I; the rest of the sample is the progeny of an old disk stellar population, with main sequence masses M<3M_{sun}_ and ages t>0.3Gyr. Our observations do not seem to imply that the metallicity gradient across the M33 disk has flattened considerably with time. We report also the discovery of a PN with Wolf-Rayet features, PN039, belonging the class of late [WC] stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/706/553
- Title:
- Fluxes in nearby star-forming galaxies
- Short Name:
- J/ApJ/706/553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Compared to starburst galaxies, normal star-forming galaxies have been shown to display a much larger dispersion of the dust attenuation at fixed reddening through studies of the IRX-{beta} diagram (the IR/UV ratio "IRX" versus the UV color "{beta}"). To investigate the causes of this larger dispersion and attempt to isolate second parameters, we have used GALEX UV, ground-based optical, and Spitzer infrared imaging of eight nearby galaxies, and examined the properties of individual UV and 24um selected star-forming regions. We concentrated on star-forming regions, in order to isolate simpler star formation histories than those that characterize whole galaxies.