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411. [CII]158um and [NII]205um IC 342 spectra
ID:
ivo://CDS.VizieR/J/A+A/591/A33
Title:
[CII]158um and [NII]205um IC 342 spectra
Short Name:
J/A+A/591/A33
Date:
21 Oct 2021
Publisher:
CDS
Description:
Atomic fine-structure line emission is a major cooling process in the interstellar medium (ISM). In particular the [CII] 158um line is one of the dominant cooling lines in photon-dominated regions (PDRs). However, it is not confined to PDRs but can also originate from the ionized gas closely surrounding young massive stars. The proportion of the [CII] emission from HII regions relative to that from PDRs can vary significantly. We investigate the question of how much of the [CII] emission in the nucleus of the nearby spiral galaxy IC 342 is contributed by PDRs and by the ionized gas. We examine the spatial variations of starburst/PDR activity and study the correlation of the [CII] line with the [NII] 205um emission line coming exclusively from the HII regions. We present small maps of [CII] 158um and [NII] 205um lines recently observed with the GREAT receiver on board SOFIA. We present different methods to utilize the superior spatial and spectral resolution of our new data to infer information on how the gas kinematics in the nuclear region influence the observed line profiles. In particular we present a super-resolution method to derive how unresolved, kinematically correlated structures in the beam contribute to the observed line shapes.
412. [CII]157.7um feature in LIRGs
ID:
ivo://CDS.VizieR/J/ApJ/774/68
Title:
[CII]157.7um feature in LIRGs
Short Name:
J/ApJ/774/68
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first results of a survey of the [CII]157.7{mu}m emission line in 241 luminous infrared galaxies (LIRGs) comprising the Great Observatories All-sky LIRG Survey (GOALS) sample, obtained with the PACS instrument on board the Herschel Space Observatory. The [CII] luminosities, L_[CII]_, of the LIRGs in GOALS range from ~10^7^ to 2x10^9^L_{sun}_.
413. [CII]158um line fluxes of AGN from Herschel
ID:
ivo://CDS.VizieR/J/ApJ/755/171
Title:
[CII]158um line fluxes of AGN from Herschel
Short Name:
J/ApJ/755/171
Date:
21 Oct 2021
Publisher:
CDS
Description:
Results are presented for [CII] 158{mu}m line fluxes observed with the Herschel PACS instrument in 112 sources with both starburst and active galactic nucleus (AGN) classifications, of which 102 sources have confident detections. Results are compared with mid-infrared spectra from the Spitzer Infrared Spectrometer and with L_ir_ from IRAS fluxes; AGN/starburst classifications are determined from equivalent width of the 6.2{mu}m polycyclic aromatic hydrocarbon (PAH) feature. It is found that the [CII] line flux correlates closely with the flux of the 11.3{mu}m PAH feature independent of AGN/starburst classification, log[f([CII]158{mu}m)/f(11.3{mu}mPAH)]=-0.22+/-0.25. It is concluded that the [CII] line flux measures the photodissociation region associated with starbursts in the same fashion as the PAH feature. A calibration of star formation rate (SFR) for the starburst component in any source having [CII] is derived comparing [CII] luminosity L([CII]) to L_ir_ with the result that logSFR=logL([CII)])-7.08+/-0.3, for SFR in M_{sun}_/yr and L([CII]) in L_{sun}_. The decreasing ratio of L([CII]) to L_ir_ in more luminous sources (the "[CII] deficit") is shown to be a consequence of the dominant contribution to L_ir_arising from a luminous AGN component because the sources with the largest L_ir_ and smallest L([CII])/L_ir_ are AGNs.
414. CI radial velocities with HST/STIS
ID:
ivo://CDS.VizieR/J/ApJ/734/65
Title:
CI radial velocities with HST/STIS
Short Name:
J/ApJ/734/65
Date:
21 Oct 2021
Publisher:
CDS
Description:
We analyzed absorption features arising from interstellar neutral carbon that appeared in the UV spectra of 89 stars recorded in the highest resolution echelle modes of the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope so that we could determine the relative populations of collisionally excited fine-structure levels in the atom's electronic ground state. From this information, in combination with molecular hydrogen rotation temperatures, we derive the distribution of thermal pressures in the diffuse, cold neutral medium (CNM). We find a lognormal pressure distribution (weighted by mass) with a mean in log(p/k) equal to 3.58 and an rms dispersion of at least 0.175dex that plausibly arises from turbulence with a characteristic Mach number in the range 1<M<4.
415. Circinus galaxy CRIRES observations
ID:
ivo://CDS.VizieR/J/A+A/549/A139
Title:
Circinus galaxy CRIRES observations
Short Name:
J/A+A/549/A139
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new CRIRES spectroscopic observations of the Br{gamma} emission line in the nuclear region of the Circinus galaxy, obtained with the aim of measuring the black hole (BH) mass with the spectroastrometric technique. The Circinus galaxy is an ideal benchmark for the spectroastrometric technique given its proximity and secure BH measurement obtained with the observation of its nuclear H_2_O maser disk. The kinematical data have been analyzed both with the classical method based on the analysis of the rotation curves and with the new method developed by us that is based on spectroastrometry. The classical method indicates that the gas disk rotates in a gravitational potential resulting from an extended stellar mass distribution and a spatially unresolved dynamical mass of (1.7+/-0.2)x10^7^M_{sun}_, concentrated within r<7pc, corresponding to the seeing-limited resolution of the observations. The new method is capable of probing the gas rotation at scales that are a factor ~3.5 smaller than those probed by the rotation curve analysis, highlighting the potential of spectroastrometry. The dynamical mass, which is spatially unresolved with the spectroastrometric method, is a factor ~2 smaller, 7.9^+1.4^_-1.1_x10^6^M_{sun}_, indicating that spectroastrometry has been able to spatially resolve the nuclear mass distribution down to 2 pc scales. This unresolved mass is still a factor ~4.5 larger than the BH mass measurement obtained with the H_2_O maser emission, indicating that even with spectroastrometry, it has not been possible to resolve the sphere of influence of the BH. Based on literature data, this spatially unresolved dynamical mass distribution is likely dominated by warm molecular gas and has been tentatively identified with the circum-nuclear torus that prevents a direct view of the central BH in Circinus. This mass distribution, with a size of ~2pc, is similar in shape to that of the star cluster of the Milky Way, suggesting that a molecular torus, forming stars at a high rate, might be the earlier evolutionary stage of the nuclear star clusters that are common in late-type spirals.
416. Circumstellar disk evolution in NGC 2068/71
ID:
ivo://CDS.VizieR/J/AJ/135/966
Title:
Circumstellar disk evolution in NGC 2068/71
Short Name:
J/AJ/135/966
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the disk and accretion properties of young stars in the NGC 2068 and NGC 2071 clusters. Using low-resolution optical spectra, we define a membership sample and determine an age for the region of ~2Myr. Using high-resolution spectra of the H{alpha} line we study the accretion activity of these likely members and also examine the disk properties of the likely members using IRAC and MIPS mid-infrared photometry. A substantial fraction (79%) of the 67 members have an infrared excess while all of the stars with significant infrared excess show evidence for active accretion. We find three populations of evolved disks (IRAC weak, MIPS weak, and transition disks) all of which show decreased accretion activity in addition to the evidence for evolution in the dust disk.
417. Circumstellar silicate grains
ID:
ivo://CDS.VizieR/J/A+A/293/833
Title:
Circumstellar silicate grains
Short Name:
J/A+A/293/833
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on the radiative transfer modelling studies relative to a large sample of circumstellar envelopes (~300 sources) undertaken by David & Papoular (1990A&A...237..425D) the complex dielectric function for circumstellar silicate grains is derived in the wavelength region from 0.35 to ~1355m.
418. CIV 1549{AA} emission line in AGNs
ID:
ivo://CDS.VizieR/J/ApJ/666/757
Title:
CIV 1549{AA} emission line in AGNs
Short Name:
J/ApJ/666/757
Date:
21 Oct 2021
Publisher:
CDS
Description:
We are exploring a spectroscopic unification for all types of broad-line emitting AGNs. The four-dimensional Eigenvector 1 (4DE1) parameter space organizes quasar diversity in a sequence primarily governed by Eddington ratio. This paper considers the role of CIV {lambda}1549 measures as 4DE1 diagnostics. We use HST archival spectra for 130 sources with S/N high enough to permit reliable CIV {lambda}1549 broad-component measures.
419. CIV absorption in DLAs and sub-DLAs systems
ID:
ivo://CDS.VizieR/J/A+A/473/791
Title:
CIV absorption in DLAs and sub-DLAs systems
Short Name:
J/A+A/473/791
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a study of CIV absorption in a sample of 63 damped Lyman-{alpha} (DLA) systems and 11 sub-DLAs in the redshift range 1.75<z_abs_<3.61, using a dataset of high-resolution (6.6km/s FWHM), high signal-to-noise VLT/UVES spectra. The complex absorption line profiles show both narrow and broad CIV components, indicating the presence of both warm, photoionized and hot, collisionally ionized gas. We report new correlations between the metallicity (measured in the neutral-phase) and each of the CIV column density, the CIV total line width, and the maximum CIV velocity.
420. CIV and FeK{alpha} Baldwin effects in AGNs
ID:
ivo://CDS.VizieR/J/ApJ/702/767
Title:
CIV and FeK{alpha} Baldwin effects in AGNs
Short Name:
J/ApJ/702/767
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use UV/optical and X-ray observations of 272 radio-quiet Type 1 active galactic nuclei and quasars to investigate the CIV Baldwin Effect (BEff). The UV/optical spectra are drawn from the Hubble Space Telescope, International Ultraviolet Explorer and Sloan Digital Sky Survey archives. The X-ray spectra are from the Chandra and XMM-Newton archives. We apply correlation and partial-correlation analyses to the equivalent widths (EWs), continuum monochromatic luminosities, and {alpha}_ox_, which characterizes the relative X-ray to UV brightness. The EW of the CIV{lambda}1549 emission line is correlated with both {alpha}_ox_ and luminosity. In our sample, narrow Fe K{alpha} 6.4keV emission lines are detected in 50 objects.

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