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2401. Space telescope RM project. VIII. NGC5548 HST sp.
ID:
ivo://CDS.VizieR/J/ApJ/881/153
Title:
Space telescope RM project. VIII. NGC5548 HST sp.
Short Name:
J/ApJ/881/153
Date:
21 Oct 2021
Publisher:
CDS
Description:
We model the ultraviolet spectra of the Seyfert 1 galaxy NGC 5548 obtained with the Hubble Space Telescope during the 6 month reverberation mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblends the individual emission lines. Using the modeled spectra, we measure the response to continuum variations for the deblended and absorption-corrected individual broad emission lines, the velocity-dependent profiles of Ly{alpha} and CIV, and the narrow and broad intrinsic absorption features. We find that the time lags for the corrected emission lines are comparable to those for the original data. The velocity-binned lag profiles of Ly{alpha} and CIV have a double-peaked structure indicative of a truncated Keplerian disk. The narrow absorption lines show a delayed response to continuum variations corresponding to recombination in gas with a density of ~10^5^cm^-3^. The high-ionization narrow absorption lines decorrelate from continuum variations during the same period as the broad emission lines. Analyzing the response of these absorption lines during this period shows that the ionizing flux is diminished in strength relative to the far-ultraviolet continuum. The broad absorption lines associated with the X-ray obscurer decrease in strength during this same time interval. The appearance of X-ray obscuration in ~2012 corresponds with an increase in the luminosity of NGC 5548 following an extended low state. We suggest that the obscurer is a disk wind triggered by the brightening of NGC 5548 following the decrease in size of the broad-line region during the preceding low-luminosity state.
2402. Space telescope RM project. V. NGC5548 sp. monitoring
ID:
ivo://CDS.VizieR/J/ApJ/837/131
Title:
Space telescope RM project. V. NGC5548 sp. monitoring
Short Name:
J/ApJ/837/131
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multiwavelength reverberation mapping campaign. The campaign spanned 6 months and achieved an almost daily cadence with observations from five ground-based telescopes. The H{beta} and HeII{lambda}4686 broad emission-line light curves lag that of the 5100{AA} optical continuum by 4.17_-0.36_^+0.36^days and 0.79_-0.34_^+0.35^days, respectively. The H{beta} lag relative to the 1158{AA} ultraviolet continuum light curve measured by the Hubble Space Telescope is ~50% longer than that measured against the optical continuum, and the lag difference is consistent with the observed lag between the optical and ultraviolet continua. This suggests that the characteristic radius of the broad-line region is ~50% larger than the value inferred from optical data alone. We also measured velocity-resolved emission-line lags for H{beta} and found a complex velocity-lag structure with shorter lags in the line wings, indicative of a broad-line region dominated by Keplerian motion. The responses of both the H{beta} and He II emission lines to the driving continuum changed significantly halfway through the campaign, a phenomenon also observed for CIV, Ly{alpha}, HeII(+OIII]), and SiIV(+OIV]) during the same monitoring period. Finally, given the optical luminosity of NGC5548 during our campaign, the measured H{beta} lag is a factor of five shorter than the expected value implied by the R_BLR_-L_AGN_ relation based on the past behavior of NGC 5548.
2403. Spatial extent of (U)LIRGs in the MIR. I.
ID:
ivo://CDS.VizieR/J/ApJ/723/993
Title:
Spatial extent of (U)LIRGs in the MIR. I.
Short Name:
J/ApJ/723/993
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of the extended mid-infrared (MIR) emission of the Great Observatories All-Sky LIRG Survey sample based on 5-15um low-resolution spectra obtained with the Infrared Spectrograph on Spitzer. We calculate the fraction of extended emission (FEE) as a function of wavelength for the galaxies in the sample, FEE_{lambda}_, defined as the fraction of the emission which originates outside of the unresolved component of a source at a given distance. We find that the FEE_{lambda}_ varies from one galaxy to another, but we can identify three general types of FEE_{lambda}_: one where FEE_{lambda}_ is constant, one where features due to emission lines and polycyclic aromatic hydrocarbons appear more extended than the continuum, and a third which is characteristic of sources with deep silicate absorption at 9.7um. The mean size of the LIRG cores at 13.2um is 2.6kpc. However, once the IR luminosity of the systems reaches the threshold of L_IR_~10^11.8^L_{sun}_, slightly below the regime of Ultra-luminous Infrared Galaxies (ULIRGs), all sources become clearly more compact, with FEE_13.2um_<~0.2, and their cores are unresolved. Our estimated upper limit for the core size of ULIRGs is less than 1.5kpc.
2404. Spatial extent of (U)LIRGs in the MIR. II.
ID:
ivo://CDS.VizieR/J/ApJ/741/32
Title:
Spatial extent of (U)LIRGs in the MIR. II.
Short Name:
J/ApJ/741/32
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from the second part of our analysis of the extended mid-infrared (MIR) emission of the GOALS sample based on 5-14um low-resolution spectra obtained with the Infrared Spectrograph on Spitzer. We calculate the fraction of extended emission (FEE) as a function of wavelength for all galaxies in the sample, FEE_{lambda}_, defined as the fraction of the emission that originates outside of the unresolved central component of a source, and spatially separate the MIR spectrum of a galaxy into its nuclear and extended components. We find that the [NeII]12.81um emission line is as compact as the hot dust MIR continuum, while the polycyclic aromatic hydrocarbon (PAH) emission is more extended. In addition, the 6.2 and 7.7um PAH emission is more compact than that of the 11.3um PAH, which is consistent with the formers being enhanced in a more ionized medium. The presence of an active galactic nucleus (AGN) or a powerful nuclear starburst increases the compactness and the luminosity surface density of the hot dust MIR continuum, but has a negligible effect on the spatial extent of the PAH emission on kpc-scales. Furthermore, it appears that both processes, AGN and/or nuclear starburst, are indistinguishable in terms of how they modify the integrated PAH-to-continuum ratio of the FEE in (ultra)luminous infrared galaxies ((U)LIRGs). Globally, the 5-14um spectra of the extended emission component are homogeneous for all galaxies in the GOALS sample.
2405. Spatial variation in fine-structure constant
ID:
ivo://CDS.VizieR/J/MNRAS/422/3370
Title:
Spatial variation in fine-structure constant
Short Name:
J/MNRAS/422/3370
Date:
21 Oct 2021
Publisher:
CDS
Description:
Quasar absorption lines provide a precise test of whether the fine-structure constant, {alpha}, is the same in different places and through cosmological time. We present a new analysis of a large sample of quasar absorption-line spectra obtained using the Ultraviolet and Visual Echelle Spectrograph (UVES) on the Very Large Telescope (VLT) in Chile. We apply the many-multiplet method to derive values of {DELTA}{alpha}/{alpha}==({alpha}z-{alpha}0)/{alpha}0 from 154 absorbers, and combine these values with 141 values from previous observations at the Keck Observatory in Hawaii.
2406. Spatiokinematics of NGC 1514
ID:
ivo://CDS.VizieR/J/AJ/126/2963
Title:
Spatiokinematics of NGC 1514
Short Name:
J/AJ/126/2963
Date:
21 Oct 2021
Publisher:
CDS
Description:
New spatiokinematic observations were undertaken of the planetary nebula NGC 1514 in the [O III] line at 5007{AA} using an imaging Fabry-Perot spectrometer. Our results show an inner ellipsoidal shell and polar blobs that do not conform to bipolar morphology. It is argued that the nebula is a descendant of a common envelope binary system the periodicity of which is estimated to be about 10 days, with a progenitor mass of 4.5M_{sun}_.
2407. Spectra and radial velocities of nuclear stars
ID:
ivo://CDS.VizieR/J/A+A/570/A2
Title:
Spectra and radial velocities of nuclear stars
Short Name:
J/A+A/570/A2
Date:
21 Oct 2021
Publisher:
CDS
Description:
Within the central 10pc of our Galaxy lies a dense cluster of stars. This nuclear star cluster forms a distinct component of the Galaxy, and similar nuclear star clusters are found in most nearby spiral and elliptical galaxies. Studying the structure and kinematics of nuclear star clusters reveals the history of mass accretion and growth of galaxy nuclei and central massive black holes. Because the Milky Way nuclear star cluster is at a distance of only 8 kpc, we can spatially resolve the cluster on sub-parsec scales. This makes the Milky Way nuclear star cluster a reference object for understanding the formation of all nuclear star clusters.
2408. Spectra classification from ISO PHT-S database
ID:
ivo://CDS.VizieR/J/ApJS/151/299
Title:
Spectra classification from ISO PHT-S database
Short Name:
J/ApJS/151/299
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have classified over 1500 infrared spectra obtained with the PHT-S spectrometer aboard the Infrared Space Observatory according to the system developed for the Short Wavelength Spectrometer (SWS) spectra by Kraemer et al. (2002ApJS..140..389K). The majority of these spectra contribute to subclasses that are either under-represented in the SWS spectral database or contain sources that are too faint, such as M dwarfs, to have been observed by either the SWS or the Infrared Astronomical Satellite Low Resolution Spectrometer. There is strong overall agreement about the chemistry of objects observed with both instruments. Discrepancies can usually be traced to the different wavelength ranges and sensitivities of the instruments. Finally, a large subset of the observations (~250 spectra) exhibit a featureless, red continuum that is consistent with emission from zodiacal dust and suggest directions for further analysis of this serendipitous measurement of the zodiacal background.
2409. Spectra & HST obs. of gal. in 1ES1553+113 field
ID:
ivo://CDS.VizieR/J/ApJ/884/L31
Title:
Spectra & HST obs. of gal. in 1ES1553+113 field
Short Name:
J/ApJ/884/L31
Date:
21 Oct 2021
Publisher:
CDS
Description:
The relationship between galaxies and the state/chemical enrichment of the warm-hot intergalactic medium (WHIM) expected to dominate the baryon budget at low-z provides sensitive constraints on structure formation and galaxy evolution models. We present a deep redshift survey in the field of 1ES1553+113, a blazar with a unique combination of ultraviolet (UV)+X-ray spectra for surveys of the circumgalactic/intergalactic medium (CGM/IGM). Nicastro+ (2018Natur.558..406N) reported the detection of two OVII WHIM absorbers at z=0.4339 and 0.3551 in its spectrum, suggesting that the WHIM is metal rich and sufficient to close the missing baryons problem. Our survey indicates that the blazar is a member of a z=0.433 group and that the higher-z OVII candidate arises from its intragroup medium. The resulting bias precludes its use in baryon censuses. The z=0.3551 candidate occurs in an isolated environment 630kpc from the nearest galaxy (with stellar mass logM_*_/M_{sun}_~9.7), which we show is unexpected for the WHIM. Finally, we characterize the galactic environments of broad HI Ly{alpha} absorbers (Doppler widths of b=40-80km/s; T<~4x10^5^K) that provide metallicity-independent WHIM probes. On average, broad Ly{alpha} absorbers are ~2x closer to the nearest luminous (L>0.25L*) galaxy (700kpc) than narrow (b<30km/s; T<~4x10^5^K) ones (1300kpc) but ~2x further than OVI absorbers (350kpc). These observations suggest that gravitational collapse heats portions of the IGM to form the WHIM, but with feedback that does not enrich the IGM far beyond galaxy/group halos to levels currently observable in UV/X-ray metal lines.
2410. Spectral analysis of 100 evolved PNe from SPM
ID:
ivo://CDS.VizieR/J/ApJ/771/114
Title:
Spectral analysis of 100 evolved PNe from SPM
Short Name:
J/ApJ/771/114
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have selected a group of 100 evolved planetary nebulae (PNe) and study their kinematics based upon spatially-resolved, long-slit, echelle spectroscopy. The data have been drawn from the San Pedro Martir Kinematic Catalogue of PNe (SPM Catalogue). The aim is to characterize in detail the global kinematics of PNe at advanced stages of evolution with the largest sample of homogenous data used to date for this purpose. The results reveal two groups that share kinematics, morphology, and photo-ionization characteristics of the nebular shell and central star luminosities at the different late stages under study. The typical flow velocities we measure are usually larger than seen in earlier evolutionary stages, with the largest velocities occurring in objects with very weak or absent [NII]{lambda}6584 line emission, by all indications the least evolved objects in our sample. The most evolved objects expand more slowly. This apparent deceleration during the final stage of PNe evolution is predicted by hydrodynamical models, but other explanations are also possible. These results provide a template for comparison with the predictions of theoretical models.

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