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1911. Optical spectroscopy of 1Jy, S4 and S5 sources
ID:
ivo://CDS.VizieR/J/A+AS/100/395
Title:
Optical spectroscopy of 1Jy, S4 and S5 sources
Short Name:
J/A+AS/100/395
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
1912. Optical spectroscopy of 1Jy, S4 and S5 sources
ID:
ivo://CDS.VizieR/J/A+AS/80/103
Title:
Optical spectroscopy of 1Jy, S4 and S5 sources
Short Name:
J/A+AS/80/103
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
1913. Optical spectroscopy of 1LAC broad-line blazars
ID:
ivo://CDS.VizieR/J/ApJ/748/49
Title:
Optical spectroscopy of 1LAC broad-line blazars
Short Name:
J/ApJ/748/49
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on optical spectroscopy of 165 flat spectrum radio quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQs show significant evidence for non-thermal emission even in the optical; the degree depends on the {gamma}-ray hardness. They also have smaller virial estimates of hole mass than the optical quasar sample. This appears to be largely due to a preferred (axial) view of the {gamma}-ray FSRQ and non-isotropic (H/R ~ 0.4) distribution of broad-line velocities. Even after correction for this bias, the Fermi FSRQs show higher mean Eddington ratios than the optical population. A comparison of optical spectral properties with Owens Valley Radio Observatory radio flare activity shows no strong correlation.
1914. Optical spectroscopy of 77 luminous AGNs and QSOs
ID:
ivo://CDS.VizieR/J/AJ/133/186
Title:
Optical spectroscopy of 77 luminous AGNs and QSOs
Short Name:
J/AJ/133/186
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present optical spectroscopy of a sample of 77 luminous active galactic nuclei (AGNs) and quasars selected on the basis of their mid-infrared colors. Our objects are selected from the Spitzer Extragalactic First Look Survey and the SWIRE XMM-Newton Large-Scale Structure Survey (XMM-LSS) fields, with a typical 24um flux density of 5mJy. The median redshift is 0.6, with a range of ~0.05-4. Only 33% (25 out of 77) of these objects are normal type 1 quasars, with no obscuration. Forty-four percent (34 out of 77) are type 2 objects, with high-ionization, narrow emission lines, and 14% (11 out of 77) are dust-reddened type 1 quasars, showing broad lines but a dust-reddened or unusually weak quasar continuum.
1915. Optical spectroscopy of 24 Ly-alpha emitters
ID:
ivo://CDS.VizieR/J/A+A/561/A89
Title:
Optical spectroscopy of 24 Ly-alpha emitters
Short Name:
J/A+A/561/A89
Date:
21 Oct 2021
Publisher:
CDS
Description:
Among the different observational techniques used to select high-redshift galaxies, the hydrogen recombination line Lyman-alpha (Ly{alpha}) is of particular interest because it gives access to the measurement of cosmological quantities such as the star formation rate (SFR) of distant galaxy populations. However, interpreting this line and calibrating such observables are still subject to serious uncertainties. In this context, it important to understand the mechanisms responsible for the attenuation of Ly{alpha} emission, and under what conditions the Ly{alpha} emission line can be used as a reliable star formation diagnostic tool. We used a sample of 24 Ly{alpha} emitters at z~0.3 with an optical spectroscopic follow-up to calculate the Ly{alpha} escape fraction and its dependence upon different physical properties. We also examined the reliability of Ly{alpha} as a SFR indicator. We combined these observations with a compilation of Ly{alpha} emitters selected at z=0-0.3 from the literature to assemble a larger sample.
1916. Optical Spectroscopy of WIYN Hydra FLS sources
ID:
ivo://CDS.VizieR/J/ApJ/663/218
Title:
Optical Spectroscopy of WIYN Hydra FLS sources
Short Name:
J/ApJ/663/218
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an optical spectroscopic survey of 24um and 1.4GHz sources, detected in the Spitzer extragalactic First Look Survey (FLS), using the multifiber spectrograph, Hydra, on the WIYN telescope. We have obtained spectra for 772 sources, with flux densities above 0.15mJy in the infrared and 0.09mJy in the radio. The redshifts measured in this survey are mostly in the range 0<z<0.4, with a distribution peaking at z~0.2.
1917. Optical spectroscopy of young {alpha}-rich stars
ID:
ivo://CDS.VizieR/J/ApJ/860/49
Title:
Optical spectroscopy of young {alpha}-rich stars
Short Name:
J/ApJ/860/49
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report chemical abundances of 14 young {alpha}-rich stars including neutron-capture elements based on high-quality optical spectra from HIRES/Keck I and differential line-by-line analysis. From a comparison of the abundance patterns of young {alpha}-rich stars to those of nearby bright red giants with a similar metallicity range (-0.7<[Fe/H]{<}-0.2), we confirm their high {alpha}-element abundances reported by previous studies based on near-infrared spectroscopy. We reveal for the first time low abundances of s-process elements and high abundances of r-process elements. All the abundances are consistent with those seen in the typical {alpha}-rich population of the Galactic disk, and no abundance anomalies are found except for Li-enhancement in one object previously reported and mild enhancement of Na in two stars. In particular, the lack of s-process enhancement excludes the hypothesis that mass transfer from asymptotic giant branch stars plays an important role in the formation of young {alpha}-rich stars. The high frequency of radial velocity variation (more than 50%) is also confirmed. We argue that mass transfer from low-mass red giants is the likely dominant formation mechanism for young {alpha}-rich stars.
1918. Optical spectroscopy toward Orion B fields
ID:
ivo://CDS.VizieR/J/ApJ/844/138
Title:
Optical spectroscopy toward Orion B fields
Short Name:
J/ApJ/844/138
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from high-resolution optical spectra toward 66 young stars in the Orion B molecular cloud to study their kinematics and other properties. Observations of the H{alpha} and Li I 6707{AA} lines are used to check membership and accretion properties. While the stellar radial velocities of NGC 2068 and L1622 are in good agreement with that of the molecular gas, many of the stars in NGC 2024 show a considerable offset. This could be a signature of either the expansion of the cluster, the high degree of the ejection of the stars from the cluster through dynamical interaction, or the acceleration of the gas due to stellar feedback.
1919. Optical spectrum of HR 4049
ID:
ivo://CDS.VizieR/J/A+A/306/924
Title:
Optical spectrum of HR 4049
Short Name:
J/A+A/306/924
Date:
21 Oct 2021
Publisher:
CDS
Description:
High-resolution optical spectra (UES/WHT) of the extreme metal-poor post-AGB star HR 4049 were obtained at four different orbital phases. The spectra cover the wavelength region from 3650A to 10850A at a resolution of R=5.2x10^4^. These observations are supplemented with four high-resolution spectra of the NaI D1 & D2 and CaII K lines at R=~10^5^ (CAT/CES). The optical spectrum shows 217 spectral lines: the Balmer series (H{alpha} - H35), the Paschen series (P9 - P23), NI, OI and numerous CI lines. We show that the lines of H{alpha}, H{beta}, H{gamma} and NaI D show significant changes in profile between different observation dates. Nine components were identified in the profile of the NaI D lines of which three are circumstellar and six interstellar. The stronger CI lines are asymmetric and we derive a post-AGB mass-loss of {dot}(M)=6+/-4x10^-7^M_{sun}_/yr from the asymmetry. The [OI]6300A line has been detected in emission at the system velocity and we argue that the emission is from an almost edge-on disk with a radius of about 20R_*_. HR 4049 is at J2000 position: 00 42 45.8 - 20 21 36
1920. Optical spectrum of M 2-24
ID:
ivo://CDS.VizieR/J/A+A/404/545
Title:
Optical spectrum of M 2-24
Short Name:
J/A+A/404/545
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have obtained medium-resolution, deep optical long-slit spectra of the bulge planetary nebula (PN) M 2-24. The spectrum covers the wavelength range from 3610-7330{AA}. Over two hundred emission lines have been detected. The spectra show a variety of optical recombination lines (ORLs) from C, N, O and Ne ions. The diagnostic diagram shows significant density and temperature variations across the nebula. Our analysis suggests that the nebula has a dense central emission core. The nebula was thus studied by dividing it into two regions: 1) an high ionization region characterized by an electron temperature of T_e_=16300K and a density of logN_e_(cm^-3^)=6.3; and 2) a low ionization region represented by T_e_=11400K and logN_e_(cm^-3^)=3.7. A large number of ORLs from C, N, O and Ne ions have been used to determine the abundances of these elements relative to hydrogen. In general, the resultant abundances are found to be higher than the corresponding values deduced from collisionally excited lines (CELs). This bulge PN is found to have large enhancements in two {alpha}-elements, magnesium and neon.

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