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641. 127 early type and pre-main-sequence stars in W4
ID:
ivo://CDS.VizieR/J/ApJ/899/121
Title:
127 early type and pre-main-sequence stars in W4
Short Name:
J/ApJ/899/121
Date:
15 Mar 2022 03:47:36
Publisher:
CDS
Description:
Stellar kinematics provides the key to understanding the formation process and dynamical evolution of stellar systems. Here, we present a kinematic study of the massive star-forming region (SFR) W4 in the Cassiopeia OB6 association using the Gaia Data Release 2 and high-resolution optical spectra. This SFR is composed of a core cluster (IC1805) and a stellar population distributed over 20pc, which is a typical structural feature found in many OB associations. According to a classical model, this structural feature can be understood in the context of the dynamical evolution of a star cluster. The core-extended structure exhibits internally different kinematic properties. Stars in the core have an almost isotropic motion, and they appear to reach virial equilibrium given their velocity dispersion (0.9{+/-}0.3km/s) comparable to that in a virial state (~0.8km/s). On the other hand, the distributed population shows a clear pattern of radial expansion. From the N-body simulation for the dynamical evolution of a model cluster in subvirial state, we reproduce the observed structure and kinematics of stars. This model cluster experiences collapse for the first 2Myr. Some members begin to radially escape from the cluster after the initial collapse, eventually forming a distributed population. The internal structure and kinematics of the model cluster appear similar to those of W4. Our results support the idea that the stellar population distributed over 20pc in W4 originate from the dynamical evolution of IC1805.
642. Early-type BCGs with star formation
ID:
ivo://CDS.VizieR/J/MNRAS/423/422
Title:
Early-type BCGs with star formation
Short Name:
J/MNRAS/423/422
Date:
21 Oct 2021
Publisher:
CDS
Description:
We identify a total of 120 early-type brightest cluster galaxies (BCGs) at 0.1<z<0.4 in two recent large cluster catalogues selected from the Sloan Digital Sky Survey (SDSS). They are selected with strong emission lines in their optical spectra, with both H{alpha} and [OII]{lambda}3727 line emission, which indicates significant ongoing star formation. They constitute about ~0.5 per cent of the largest, optically selected, low-redshift BCG sample, and the fraction is a strong function of cluster richness. Their star formation history can be well described by a recent minor and short starburst superimposed on an old stellar component, with the recent episode of star formation contributing on average only less than 1 per cent of the total stellar mass. We show that the more massive star-forming BCGs in richer clusters tend to have higher star formation rate (SFR) and specific SFR (SFR per unit galaxy stellar mass). We also compare their statistical properties with a control sample selected from X-ray luminous clusters, and show that the fraction of star-forming BCGs in X-ray luminous clusters is almost one order of magnitude larger than that in optically selected clusters. BCGs with star formation in cooling flow clusters usually have very flat optical spectra and show the most active star formation, which may be connected with cooling flows.
643. EBHIS spectra and HI column density maps
ID:
ivo://CDS.VizieR/J/A+A/585/A41
Title:
EBHIS spectra and HI column density maps
Short Name:
J/A+A/585/A41
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Effelsberg-Bonn HI Survey (EBHIS) is a new 21-cm survey performed with the 100-m telescope at Effelsberg. It covers the whole northern sky out to a redshift of z~0.07 and comprises HI line emission from the Milky Way and the Local Volume. We aim to substitute the northern-hemisphere part of the Leiden/Argentine/Bonn Milky Way HI survey (LAB) with this first EBHIS data release, which presents the HI gas in the Milky Way regime. The use of a seven-beam L-band array made it feasible to perform this all-sky survey with a 100-m class telescope in a reasonable amount of observing time. State-of-the-art fast-Fourier-transform spectrometers provide the necessary data read-out speed, dynamic range, and spectral resolution to apply software radio-frequency interference mitigation. EBHIS is corrected for stray radiation and employs frequency-dependent flux-density calibration and sophisticated baseline-removal techniques to ensure the highest possible data quality. Detailed analyses of the resulting data products show that EBHIS is not only outperforming LAB in terms of sensitivity and angular resolution, but also matches the intensity-scale of LAB extremely well, allowing EBHIS to be used as a drop-in replacement for LAB. Data products are made available to the public in a variety of forms. Most important, we provide a properly gridded Milky Way HI column density map in HEALPix representation. To maximize the usefulness of EBHIS data, we estimate uncertainties in the HI column density and brightness temperature distributions, accounting for systematic effects.
644. EBLM J2349-32 photometry, RV and spectra
ID:
ivo://CDS.VizieR/J/A+A/626/A119
Title:
EBLM J2349-32 photometry, RV and spectra
Short Name:
J/A+A/626/A119
Date:
21 Oct 2021
Publisher:
CDS
Description:
Some M-dwarfs around F-/G-type stars have been measured to be hotter and larger than predicted by stellar evolution models. Inconsistencies between observations and models need to be addressed with more mass, radius, and luminosity measurements of low-mass stars to test and refine evolutionary models. Our aim is to measure the masses, radii and ages of the stars in five low-mass eclipsing binary systems discovered by the WASP survey. We used WASP photometry to establish eclipse-time ephemerides and to obtain initial estimates for the transit depth and width. Radial velocity measurements were simultaneously fitted with follow-up photometry to find the best-fitting orbital solution. This solution was combined with measurements of atmospheric parameters to interpolate evolutionary models and estimate the mass of the primary star, and the mass and radius of the M-dwarf companion. We assess how the best fitting orbital solution changes if an alternative limb-darkening law is used and quantify the systematic effects of unresolved companions. We also gauge how the best-fitting evolutionary model changes if different values are used for the mixing length parameter and helium enhancement. We report the mass and radius of five M-dwarfs and find little evidence of inflation with respect to evolutionary models. The primary stars in two systems are near the "blue hook" stage of their post sequence evolution, resulting in two possible solutions for mass and age. We find that choices in helium enhancement and mixing-length parameter can introduce an additional 3-5% uncertainty in measured M-dwarf mass. Unresolved companions can introduce an additional 3-8% uncertainty in the radius of an M-dwarf, while the choice of limb-darkening law can introduce up to an additional 2% uncertainty. The choices in orbital fitting and evolutionary models can introduce significant uncertainties in measurements of physical properties of such systems.
645. Echelle spectra of 10 bright asteroids
ID:
ivo://CDS.VizieR/J/A+A/462/795
Title:
Echelle spectra of 10 bright asteroids
Short Name:
J/A+A/462/795
Date:
21 Oct 2021
Publisher:
CDS
Description:
Echelle spectra of 10 bright asteroids are presented and compared against an observed twilight spectrum and a computed Solar spectrum. Spectra covering a 2130{AA} spectral range centered on 5785{AA} are of high resolving power and high signal to noise ratio. We compare detailed properties of spectral lines and not albedo variations. It is shown that the normalized Solar and asteroid spectra are identical except for radial velocity (RV) shifts which can be predicted at accuracy level of 1m/s. So asteroids are proposed as new and extremely accurate radial velocity standards. Predicted and measured RVs of observed asteroids match within the limits of accuracy of the instrument. There are numerous absorption lines in the reflected Solar spectrum. This allows a direct mapping of the resolving power of a spectrograph between and along echelle spectral orders. Thus asteroid spectra can be used to test the wavelength calibration and resolving power of spectrographs on the ground as well as in space, including the Gaia mission of ESA.
646. Echelle spectroscopy of {delta} Vel
ID:
ivo://CDS.VizieR/J/A+A/528/A21
Title:
Echelle spectroscopy of {delta} Vel
Short Name:
J/A+A/528/A21
Date:
21 Oct 2021
Publisher:
CDS
Description:
The nearby multiple system delta Velorum contains a widely detached eclipsing binary and a third component. We take advantage of this system offering the opportunity to determine the set of fundamental parameters (masses, luminosities, and radii) of three coeval stars with sufficient precision to test models of stellar evolution. Extensive high-resolution spectroscopy is analyzed by the broadening function technique to provide the first spectroscopic orbit of the eclipsing pair. Simultaneous analysis of the spectroscopic data and the SMEI satellite light curve is performed to provide astrophysical parameters for the components. We use a modified Roche model assuming an eccentric orbit and asynchronous rotation. The observations show that components of the eclipsing pair rotate at about two-thirds of the break-up velocity, which excludes any chemical peculiarity and results in a non-uniform surface brightness. Although the inner orbit is eccentric, no apsidal motion is seen during the SMEI photometric observations. For the inner orbit, the orbital parameters are eccentricity e=0.290, longitude of the periastron passage omega=109{deg}, and inclination 89.0{deg}. The component masses of M(Aa)=2.53+/-0.11M_{sun}_, M(Ab)=2.37+/-0.10M_{sun}_, and M(B)~1.5M_{sun}_ combined with the inferred radii of the Aa and Ab components indicate that the eclipsing pair has already left the main sequence and that the estimated age of the system is about 400Myr.
647. Eclipsing binaries in NGC6791
ID:
ivo://CDS.VizieR/J/A+A/525/A2
Title:
Eclipsing binaries in NGC6791
Short Name:
J/A+A/525/A2
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present photometric and spectroscopic observations of eclipsing binaries and single stars, which are members of the open cluster NGC6791. These were used to measure precise and accurate masses, radii and metallicity of the stars along with reddening and distance modulus to the cluster.
648. EDD: All Digital HI profile catalog
ID:
ivo://CDS.VizieR/J/AJ/138/1938
Title:
EDD: All Digital HI profile catalog
Short Name:
J/AJ/138/1938
Date:
21 Oct 2021
Publisher:
CDS
Description:
An important component of the Extragalactic Distance Database is a group of catalogs related to the measurement of HI line profile parameters. One of these is the All Digital HI catalog which contains an amalgam of information from new data and old. The new data result from observations with Arecibo and Parkes Telescopes and with the Green Bank Telescope, including continuing input since the award of the NRAO Cosmic Flows Large Program. The old data have been collected from archives, wherever available, particularly the Cornell University Digital HI Archive, the Nancay Telescope extragalactic HI archive, and the Australia Telescope HI archive. The catalog currently contains information on ~15000 profiles relating to ~13000 galaxies. The channel-flux per channel files, from whatever source, is carried through a common pipeline. The derived parameter of greatest interest is W_m50_, the profile width at 50% of the mean flux. After appropriate adjustment, the parameter W_mx_ is derived, the line width that statistically approximates the peak-to-peak maximum rotation velocity before correction for inclination, 2V_max_sini.
649. EELGs out to z~1 in zCOSMOS
ID:
ivo://CDS.VizieR/J/A+A/578/A105
Title:
EELGs out to z~1 in zCOSMOS
Short Name:
J/A+A/578/A105
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present line measurements and physical properties of a sample of 165 extreme emission-line galaxies (EELGs) in the zCOSMOS 20k-Bright Survey (Lilly et al., 2009, Cat. J/ApJS/184/218). The zCOSMOS spectra consist of ~1h integrations in the medium resolution LRRED grism setting (R~600 with 2.5{AA}/pixel), covering a wavelength range 5550<{lambda}<9650{AA}. Measured emission-line fluxes are given in units of 10^-17^erg/s/cm^2^. Flux errors have been derived following Perez-Montero et al. (2013A&A...549A..25P) and Amorin et al. (2012ApJ...749..185A and 2012ApJ...754L..22A). No extinction correction has been applied to these fluxes. For each galaxy the reddening constant, c(H{beta}), is presented. These values and their corresponding uncertainties have been derived from the H{alpha}/H{beta} or H{gamma}/H{beta} ratios, whenever possible. A reddening constant derived from the SED best-fitting was adopted for (a) those galaxies where the computation of c(H{beta}) from emission lines is not possible because of the lack of lines, or (b) the corresponding line ratio produces a negative extinction correction (i.e., Ha/Hb<2.82 or Hg/Hb<0.47, assuming Case B recombination with T_e_=2*10^4K, n_e_=100cm^-3^). Stellar mass and 1{sigma} uncertainties have been obtained from SED fitting (Bolzonella et al., 2010A&A...524A..76B) after removal of the flux contribution from strong emission lines.
650. EFAR Catalog. VII.
ID:
ivo://CDS.VizieR/J/MNRAS/321/277
Title:
EFAR Catalog. VII.
Short Name:
J/MNRAS/321/277
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present peculiar velocities for 85 clusters of galaxies in two large volumes at distances between 6000 and 15000km/s in the directions of Hercules-Corona Borealis and Perseus-Pisces-Cetus (the EFAR sample). These velocities are based on Fundamental Plane (FP) distance estimates for early-type galaxies in each cluster. We fit the FP using a maximum likelihood algorithm which accounts for both selection effects and measurement errors, and yields FP parameters with smaller bias and variance than other fitting procedures. We obtain a best-fitting FP with coefficients consistent with the best existing determinations. We measure the bulk motions of the sample volumes using the 50 clusters with the best-determined peculiar velocities.

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