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761. FeII emission in quasars
ID:
ivo://CDS.VizieR/J/ApJ/687/78
Title:
FeII emission in quasars
Short Name:
J/ApJ/687/78
Date:
21 Oct 2021
Publisher:
CDS
Description:
Broad FeII emission is a prominent feature of the optical and ultraviolet spectra of quasars. We report on a systematical investigation of optical FeII emission in a large sample of 4037 z<0.8 quasars selected from the SDSS-DR5 quasar catalog (Cat. VII/252). We have developed and tested a detailed line-fitting technique, taking into account the complex continuum and narrow and broad emission-line spectra. Our primary goal is to quantify the velocity broadening and velocity shift of the FeII spectrum in order to constrain the location of the FeII-emitting region and its relation to the broad-line region. We find that the majority of quasars show FeII emission that is redshifted, typically by ~400km/s, but up to 2000km/s, with respect to the systemic velocity of the narrow-line region or of the conventional broad-line region as traced by the H{beta} line. Moreover, the line width of FeII is significantly narrower than that of the broad component of H{beta}. We show that the magnitude of the FeII redshift correlates inversely with the Eddington ratio, and that there is a tendency for sources with redshifted FeII emission to show red asymmetry in the H{beta} line. These characteristics strongly suggest that FeII originates from a location different from, and most likely exterior to, the region that produces most of H{beta}. The FeII-emitting zone traces a portion of the broad-line region of intermediate velocities whose dynamics may be dominated by infall.
762. FeII emission in SDSS type 1 AGNs
ID:
ivo://CDS.VizieR/J/ApJ/736/86
Title:
FeII emission in SDSS type 1 AGNs
Short Name:
J/ApJ/736/86
Date:
21 Oct 2021
Publisher:
CDS
Description:
We used a large, homogeneous sample of 4178 z<=0.8 Seyfert 1 galaxies and QSOs selected from the Sloan Digital Sky Survey to investigate the strength of FeII emission and its correlation with other emission lines and physical parameters of active galactic nuclei. We find that the strongest correlations of almost all the emission-line intensity ratios and equivalent widths (EWs) are with the Eddington ratio (L/L_Edd_), rather than with the continuum luminosity at 5100{AA} (L_5100_) or black hole mass (M_BH_); the only exception is the EW of ultraviolet FeII emission, which does not correlate at all with broad-line width, L_5100_, M_BH_, or L/L_Edd_. By contrast, the intensity ratios of both the ultraviolet and optical FeII emission to MgII{lambda}2800 correlate quite strongly with L/L_Edd_. Interestingly, among all the emission lines in the near-UV and optical studied in this paper (including MgII{lambda}2800, H{beta}, and [OIII]{lambda}5007), the EW of narrow optical FeII emission has the strongest correlation with L/L_Edd_. We hypothesize that the variation of the emission-line strength in active galaxies is regulated by L/L_Edd_ because it governs the global distribution of the hydrogen column density of the clouds gravitationally bound in the line-emitting region, as well as its overall gas supply. The systematic dependence on L/L_Edd_ must be corrected when using the FeII/MgII intensity ratio as a measure of the Fe/Mg abundance ratio to study the history of chemical evolution in QSO environments.
763. Fe II emission lines of RR Tel
ID:
ivo://CDS.VizieR/J/A+A/381/507
Title:
Fe II emission lines of RR Tel
Short Name:
J/A+A/381/507
Date:
21 Oct 2021
Publisher:
CDS
Description:
Files table1.dat and table2.dat contain the permitted and forbidden Fe II emission lines respectively which have been selected from the optical spectrum of RR Tel between 3180 and 9455{AA}. The spectrum was observed by Crawford et al. (1999, Cat. <J/A+AS/139/135>) whose corrected line fluxes and velocity widths we took for further analysis in this work. In the tables there are also values characteristic for the corresponding multiplets and lines such as multiplet numbers, term designations, level excitation potentials and quantum numbers J. The log functions of gf's, line fluxes and wavelengths are relevant for the SAC curves.
764. FeI lines in NIR spectra of Arcturus & mu Leo
ID:
ivo://CDS.VizieR/J/ApJ/875/129
Title:
FeI lines in NIR spectra of Arcturus & mu Leo
Short Name:
J/ApJ/875/129
Date:
21 Oct 2021
Publisher:
CDS
Description:
For a detailed analysis of stellar chemical abundances, high-resolution spectra in the optical have mainly been used, while the development of near-infrared (NIR) spectrograph has opened new wavelength windows. Red giants have a large number of resolved absorption lines in both the optical and NIR wavelengths, but the characteristics of the lines in different wave passbands are not necessarily the same. We present a selection of FeI lines in the z', Y, and J bands (0.91-1.33{mu}m). On the basis of two different lists of lines in this range, the Vienna Atomic Line Database (VALD) and the catalog published by Melendez & Barbuy in 1999 (MB99; Cat. J/ApJS/124/527), we selected sufficiently strong lines that are not severely blended and compiled lists with 107 FeI lines in total (97 and 75 lines from VALD and MB99, respectively). Combining our lists with high-resolution ({lambda}/{Delta}{lambda}=28000) and high signal-to-noise (>500) spectra taken with an NIR spectrograph, WINERED, we present measurements of the iron abundances of two prototype red giants: Arcturus and {mu} Leo. A bootstrap method for determining the microturbulence and abundance together with their errors is demonstrated. The standard deviations of log{epsilon}_Fe_ values from individual FeI lines are significantly smaller when we use the lines from MB99 instead of those from VALD. With the MB99 list, we obtained {xi}=1.20+/-0.11km/s and log{epsilon}_Fe_=7.01+/-0.05dex for Arcturus, and {xi}=1.54+/-0.17km/s and log{epsilon}_Fe_=7.73+/-0.07dex for {mu} Leo. These final values show better agreements with previous values in the literature than the corresponding values we obtained with VALD.
765. FeI oscillator strengths for Gaia-ESO
ID:
ivo://CDS.VizieR/J/MNRAS/441/3127
Title:
FeI oscillator strengths for Gaia-ESO
Short Name:
J/MNRAS/441/3127
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Gaia-ESO Public Spectroscopic Survey (GES) is conducting a large-scale study of multi-element chemical abundances of some 100000 stars in the Milky Way with the ultimate aim of quantifying the formation history and evolution of young, mature and ancient Galactic populations. However, in preparing for the analysis of GES spectra, it has been noted that atomic oscillator strengths of important FeI lines required to correctly model stellar line intensities are missing from the atomic data base. Here, we present new experimental oscillator strengths derived from branching fractions and level lifetimes, for 142 transitions of FeI between 3526 and 10864{AA}, of which at least 38 are urgently needed by GES. We also assess the impact of these new data on solar spectral synthesis and demonstrate that for 36 lines that appear unblended in the Sun, Fe abundance measurements yield a small line-by-line scatter (0.08dex) with a mean abundance of 7.44dex in good agreement with recent publications.
766. FeI radiative lifetime and branching fractions
ID:
ivo://CDS.VizieR/J/ApJS/215/23
Title:
FeI radiative lifetime and branching fractions
Short Name:
J/ApJS/215/23
Date:
21 Oct 2021
Publisher:
CDS
Description:
New radiative lifetimes, measured to +/-5% accuracy, are reported for 31 even-parity levels of Fe I ranging from 45061cm^-1^ to 56842cm^-1^. These lifetimes have been measured using single-step and two-step time-resolved laser-induced fluorescence on a slow atomic beam of iron atoms. Branching fractions have been attempted for all of these levels, and completed for 20 levels. This set of levels represents an extension of the collaborative work reported in Ruffoni et al. (2013ApJ...779...17R; 2014, J/MNRAS/441/3127). The radiative lifetimes combined with the branching fractions yields new oscillator strengths for 203 lines of Fe I. Utilizing a 1D-LTE model of the solar photosphere, spectral syntheses for a subset of these lines which are unblended in the solar spectrum yields a mean iron abundance of <log[{epsilon}(Fe)]>=7.45+/-0.06.
767. FeK lines in Seyfert 1 galaxies
ID:
ivo://CDS.VizieR/J/MNRAS/426/2522
Title:
FeK lines in Seyfert 1 galaxies
Short Name:
J/MNRAS/426/2522
Date:
21 Oct 2021
Publisher:
CDS
Description:
We construct full broad-band models in an analysis of Suzaku observations of nearby Seyfert 1 active galactic nuclei (AGN) (z<=0.2) with exposures >50ks and with greater than 30000 counts in order to study their iron line profiles. This results in a sample of 46 objects and 84 observations. After a full modelling of the broad-band Suzaku and Swift-Burst Alert Telescope data (0.6-100keV), we find complex warm absorption is present in 59 per cent of the objects in this sample which has a significant bearing upon the derived FeK region parameters. Meanwhile 35 per cent of the 46 objects require some degree of high column density partial coverer in order to fully model the hard X-ray spectrum. We also find that a large number of the objects in the sample (22 per cent) require high velocity, high ionization outflows in the FeK region resulting from FeXXV and FeXXVI. A further four AGN feature highly ionized FeK absorbers consistent with zero outflow velocity, making a total of 14/46 (30%) AGN in this sample showing evidence for statistically significant absorption in the FeK region.
768. Fe-rich silicate analogues mass absorption coeff.
ID:
ivo://CDS.VizieR/J/A+A/606/A50
Title:
Fe-rich silicate analogues mass absorption coeff.
Short Name:
J/A+A/606/A50
Date:
21 Oct 2021
Publisher:
CDS
Description:
To model the cold dust emission observed in the diffuse interstellar medium, in dense molecular clouds or in cold clumps that could eventually form new stars, it is mandatory to know the physical and spectroscopic properties of this dust and to understand its emission. This work is a continuation of previous studies aiming at providing astronomers with spectroscopic data of realistic cosmic dust analogues for the interpretation of observations. The aim of the present work is to extend the range of studied analogues to iron-rich silicate dust analogues. Ferromagnesium amorphous silicate dust analogues were produced by a sol-gel method with a mean composition close to Mg_1-x_Fe_x_SiO_3_ with x=0.1, 0.2, 0.3, 0.4. Part of each sample was annealed at 500{deg}C for two hours in a reducing atmosphere to modify the oxidation state of iron. We have measured the mass absorption coefficient (MAC) of these eight ferromagnesium amorphous silicate dust analogues in the spectral domain 30-1000um for grain temperature in the range 10-300K and at room temperature in the 5-40um range. The MAC of ferromagnesium samples behaves in the same way as the MAC of pure Mg-rich amorphous silicate samples. In the 30-300K range, the MAC increases with increasing grain temperature whereas in the range 10-30K, we do not see any change of the MAC. The MAC cannot be described by a single power law in {lambda}^-{beta}^. The MAC of the samples does not show any clear trend with the iron content. However the annealing process has, on average, an effect on the MAC that we explain by the evolution of the structure of the samples induced by the processing. The MAC of all the samples is much higher than the MAC calculated by dust models. The complex behavior of the MAC of amorphous silicates with wavelength and temperature is observed whatever the exact silicate composition (Mg vs. Fe amount). It is a universal characteristic of amorphous materials, and therefore of amorphous cosmic silicates, that should be taken into account in astronomical modeling. The enhanced MAC of the measured samples compared to the MAC calculated for cosmic dust model implies that dust masses are overestimated by the models.
769. Fermi and Swift GRBs E_peak_-E_iso_ relation
ID:
ivo://CDS.VizieR/J/A+A/557/A100
Title:
Fermi and Swift GRBs E_peak_-E_iso_ relation
Short Name:
J/A+A/557/A100
Date:
21 Oct 2021
Publisher:
CDS
Description:
We used a sample of gamma-ray bursts (GRBs) detected by Fermi and Swift to reanalyze the correlation discovered by Amati et al. (2002A&A...390...81A) between E_pi_, the peak energy of the prompt GRB emission, and E_iso_, the energy released by the GRB assuming isotropic emission. This correlation has been disputed by various authors, and our aim is to assess whether it is an intrinsic GRB property or the consequence of selection effects. We constructed a sample of Fermi GRBs with homogeneous selection criteria, and we studied their distribution in the E_pi_-E_iso_ plane. Our sample is made of 43 GRBs with a redshift and 243 GRBs without a redshift. We show that GRBs with a redshift follow a broad E_pi_-E_iso_ relation, while GRBs without a redshift show several outliers. We use these samples to discuss the impact of selection effects associated with GRB detection and with redshift measurement.
770. FEROS Public Spectra
ID:
ivo://org.gavo.dc/feros/q/ssa
Title:
FEROS Public Spectra
Short Name:
FEROS SSAP
Date:
27 Dec 2024 08:31:01
Publisher:
The GAVO DC team
Description:
Spectra from FEROS spectrograph at La Silla's 1.5m telescope as obtained during commissioning and guaranteed time.

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