- ID:
- ivo://CDS.VizieR/J/MNRAS/368/253
- Title:
- Faint emission lines in M16, M20, NGC 3603
- Short Name:
- J/MNRAS/368/253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep echelle spectrophotometry of the Galactic HII regions M16, M20 and NGC 3603. The data have been taken with the Very Large Telescope Ultraviolet-Visual Echelle Spectrograph in the 3100-10400{AA} range. We have detected more than 200 emission lines in each region. Physical conditions have been derived using different continuum and line intensity ratios. We have derived He^+^, C^++^ and O^++^ abundances from pure recombination lines as well as collisionally excited lines (CELs) for a large number of ions of different elements.
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- ID:
- ivo://CDS.VizieR/J/ApJS/96/461
- Title:
- Far-UV Point Sources from FAUST
- Short Name:
- J/ApJS/96/461
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We list the photometric measurements of point sources made by the Far Ultraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 space shuttle mission. The list contains 4698 Galactic and extragalactic objects detected in 22 wide-field images of the sky. At the locations surveyed, this catalog reaches a limiting magnitude approximately a factor of 10 fainter than the previous UV all-sky survey, TD1. The catalog limit is approximately 1x10^-14^ergs/s/cm^26/A, although it is not complete to this level. We list for each object the position, FUV flux, the error in flux, and where possible an identification from catalogs of nearby stars and galaxies. These catalogs include the Michigan HD (MHD) and HD, SAO, the HIPPARCOS Input Catalog, the Position and Proper Motion Catalog, the TD1 Catalog, the McCook and Sion Catalog of white dwarf stars, and the RC3 Catalog of Galaxies. We identify 2239 FAUST sources with objects in the stellar catalogs and 172 with galaxies in the RC3 catalog. We estimate the number of sources with incorrect identifications to be less than 2%. FAUST is a wide-field telescope (7.6{deg} diameter) designed to image diffuse and point sources in the wavelength range 140-180nm. The experiment, the mission and the data are described in a previous paper by Bowyer et al., 1993ApJ...415..875B .
- ID:
- ivo://CDS.VizieR/J/A+A/554/A27
- Title:
- 2011fe spectrophotometric time series
- Short Name:
- J/A+A/554/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 32 epochs of optical (3300-9700{AA}) spectrophotometric observations of the nearby quintessential "normal" type Ia supernova (SN Ia) SN 2011fe in the galaxy M101, extending from -15 to +97d with respect to B-band maximum, obtained by the Nearby Supernova Factory collaboration. SN 2011fe is the closest ({mu}=29.04) and brightest (Bmax=9.94mag) SN Ia observed since the advent of modern large scale programs for the intensive periodic followup of supernovae. Both synthetic light curve measurements and spectral feature analysis attest to the normality of SN 2011fe. There is very little evidence for reddening in its host galaxy. The homogeneous calibration, intensive time sampling, and high signal-to-noise ratio of the data set make it unique. Thus it is ideal for studying the physics of SN Ia explosions in detail, and for furthering the use of SNe Ia as standardizable candles for cosmology.
- ID:
- ivo://CDS.VizieR/J/A+A/304/347
- Title:
- 40 field red supergiants in the SMC
- Short Name:
- J/A+A/304/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Low-resolution spectra (~5A) for 40 red supergiants in the Small Magellanic Cloud were compared with synthetic spectra, and their metallicities were derived. A mean metallicity of [Fe/He]=-0.71 is found for 38 stars cooler than T_eff_<4500K. Using the stellar parameters derived, the carbon abundances were determined by comparing synthetic spectra at the G-band region to the observed spectra. A mean {epsilon}(C)=7.85 is found, clearly higher than the low values suggested in the literature for the H II regions.
- ID:
- ivo://CDS.VizieR/J/A+A/603/A58
- Title:
- Full spectrum of Proxima Centauri
- Short Name:
- J/A+A/603/A58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The discovery of Proxima b, a terrestrial temperate planet, presents the opportunity of studying a potentially habitable world in optimal conditions. A key aspect to model its habitability is to understand the radiation environment of the planet in the full spectral domain. We characterize the X-rays to mid-IR radiative properties of Proxima with the goal of providing the top-of-atmosphere fluxes on the planet. We also aim at constraining the fundamental properties of the star, namely its mass, radius, effective temperature and luminosity. We employ observations from a large number of facilities and make use of different methodologies to piece together the full spectral energy distribution of Proxima. In the high-energy domain, we pay particular attention to the contribution by rotational modulation, activity cycle, and flares so that the data provided are representative of the overall radiation dose received by the atmosphere of the planet.
- ID:
- ivo://CDS.VizieR/J/ApJ/724/748
- Title:
- Galactic anticenter PNe and oxygen abundance
- Short Name:
- J/ApJ/724/748
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained spectrophotometric observations of 41 anticenter planetary nebulae (PNe) located in the disk of the Milky Way. Electron temperatures and densities, as well as chemical abundances for He, N, O, Ne, S, Cl, and Ar were determined. Incorporating these results into our existing database of PN abundances (Henry et al., 2004AJ....127.2284H, Milingo et al., 2010, Cat. J/ApJ/711/619) yielded a sample of 124 well-observed objects with homogeneously determined abundances extending from 0.9 to 21kpc in galactocentric distance. We performed a detailed regression analysis which accounted for uncertainties in both oxygen abundances and radial distances in order to establish the metallicity gradient across the disk to be 12+log(O/H)=(9.09+/-0.05)-(0.058+/-0.006)xR_g_, with R_g_ in kpc. While we see some evidence that the gradient steepens at large galactocentric distances, more objects toward the anticenter need to be observed in order to confidently establish the true form of the metallicity gradient.
- ID:
- ivo://CDS.VizieR/J/ApJS/176/414
- Title:
- Galaxy clusters in the SDSS-DR5
- Short Name:
- J/ApJS/176/414
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent large-scale galaxy spectroscopic surveys, such as the Sloan Digital Sky Survey (SDSS), enable us to execute a systematic, relatively unbiased search for galaxy clusters. Such surveys make it possible to measure the 3D distribution of galaxies but are hampered by the incompleteness problem due to fiber collisions. In this study we aim to develop a density-measuring technique that alleviates the problem and derives densities more accurately by adding additional cluster member galaxies that follow optical color-magnitude relations for the given redshift. The new density measured with both spectroscopic and photometric data shows a good agreement with apparent information on cluster images and is supported by follow-up observations. By adopting this new method, a total of 924 robust galaxy clusters are found from the SDSS DR5 database in the redshift range 0.05<z<0.1, of which 212 are new. Local maximum-density galaxies successfully represent cluster centers. We provide the cluster catalog including a number of cluster parameters.
- ID:
- ivo://CDS.VizieR/J/ApJ/789/135
- Title:
- Gamma-ray bright blazars spectrophotometry
- Short Name:
- J/ApJ/789/135
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present {gamma}-ray, X-ray, ultraviolet, optical, and near-infrared light curves of 33 {gamma}-ray bright blazars over 4 years that we have been monitoring since 2008 August with multiple optical, ground-based telescopes and the Swift satellite, and augmented by data from the Fermi Gamma-ray Space Telescope and other publicly available data from Swift. The sample consists of 21 flat-spectrum radio quasars (FSRQs) and 12 BL Lac objects (BL Lacs). We identify quiescent and active states of the sources based on their {gamma}-ray behavior. We derive {gamma}-ray, X-ray, and optical spectral indices, {alpha}_{gamma}_, {alpha}_X_, and {alpha}_o_, respectively (F_{nu}_{prop.to}{nu}^{alpha}^), and construct spectral energy distributions during quiescent and active states. We analyze the relationships between different spectral indices, blazar classes, and activity states. We find (1) significantly steeper {gamma}-ray spectra of FSRQs than for BL Lacs during quiescent states, but a flattening of the spectra for FSRQs during active states while the BL Lacs show no significant change; (2) a small difference of {alpha}_X_ within each class between states, with BL Lac X-ray spectra significantly steeper than in FSRQs; (3) a highly peaked distribution of X-ray spectral slopes of FSRQs at ~ -0.60, but a very broad distribution of {alpha}_X_of BL Lacs during active states; (4) flattening of the optical spectra of FSRQs during quiescent states, but no statistically significant change of {alpha}_o_ of BL Lacs between states; and (5) a positive correlation between optical and {gamma}-ray spectral slopes of BL Lacs, with similar values of the slopes. We discuss the findings with respect to the relative prominence of different components of high-energy and optical emission as the flux state changes.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A96
- Title:
- GTC spectra of z~2.3 quasars
- Short Name:
- J/A+A/570/A96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The advent of 8-10m class telescopes for the first time makes it possible to compare in detail quasars with similar luminosity and very different redshifts. We conducted a search for z-dependent gradients in line-emission diagnostics and derived physical properties by comparing, in a narrow bolometric luminosity range (logL~46.1+/-0.4erg/s), some of the most luminous local z<0.6 quasars with some of the lowest luminosity sources yet found at redshift z=2.1-2.5. Moderate signal-to-noise ratio spectra for 22 high-redshift sources were obtained with the 10.4m Gran Telescopio Canarias (GTC), for which the HST (largely the Faint Object Spectrograph) archive provides a low-redshift control sample. We compared the spectra in the context of the 4D Eigenvector 1 formalism, meaning that we divided both source samples into highly accreting population A and population B sources accreting at a lower rate. CIV {lambda}1549, the strongest and most reliable diagnostic line, shows very similar properties at both redshifts, which confirms the CIV {lambda}1549 profile differences at high redshift between populations A and B, which are well established in local quasars. The CIV {lambda}1549 blueshift that appears quasi-ubiquitous in higher L sources is found in only half (population A) of the quasars observed in the two samples. A CIV {lambda}1549 evolutionary Baldwin effect is certainly disfavored. We find evidence for lower metallicity in the GTC sample that may point toward a gradient with z. No evidence for a gradient in black hole mass or Eddington ratio is found. Spectroscopic differences established at low z are also present in much higher redshift quasars. Our results on the CIV {lambda}1549 blueshift suggest that it depends both on source luminosity and Eddington ratio. Given that our samples involve sources with very similar luminosity, the evidence for a systematic metallicity decrease, if real, points toward an evolutionary effect. Our samples are not large enough to effectively constrain possible changes of black hole mass or Eddington ratio with redshift. The two samples appear representative of a slowly evolving quasar population that is most likely present at all redshifts.
- ID:
- ivo://CDS.VizieR/J/A+AS/91/285
- Title:
- HII galaxies spectrophotometric catalogue
- Short Name:
- J/A+AS/91/285
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectrophotometric catalogue of 425 emission line galaxies discovered in objective prism surveys for which we derived redshifts, emission line intensities, equivalent widths, and absolute fluxes. The vast majority of objects in the catalogue are HII region-like galaxies (HII galaxies). In more than 80 HII galaxies the line [OIII]{lambda}4363 was measured with accuracy good enough to permit precise electron temperature determinations. The observational parameters that define the properties of HII galaxies as a class are characterized and discussed.
