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2841. CII emission-line stars in LMC with MagE spectra
ID:
ivo://CDS.VizieR/J/ApJ/898/85
Title:
CII emission-line stars in LMC with MagE spectra
Short Name:
J/ApJ/898/85
Date:
21 Mar 2022 08:48:14
Publisher:
CDS
Description:
We present a narrowband imaging survey of the Large Magellanic Cloud (LMC), designed to isolate the CII{lambda}{lambda}7231,7236 emission lines in objects as faint as m_{lambda}7400_~18. The work is motivated by the recent serendipitous discovery in the LMC of the first confirmed extragalactic [WC11] star, whose spectrum is dominated by CII emission, and the realization that the number of such objects is currently largely unconstrained. The survey, which imaged ~50deg^2^ using on-band and off-band filters, will significantly increase the total census of these rare stars. In addition, each new LMC [WC] star has a known luminosity, a quantity quite uncertain in the Galactic sample. Multiple known CII emitters were easily recovered, validating the survey design. We find 38 new CII emission candidates; spectroscopy of the complete sample will be needed to ascertain their nature. In a preliminary spectroscopic reconnaissance, we observed three candidates, finding CII emission in each. One is a new [WC11]. Another shows both the narrow CII emission lines characteristic of a [WC11], but also broad emission of CIV, OV, and HeII characteristic of a much hotter [WC4] star; we speculate that this is a binary [WC]. The third object shows weak CII emission, but the spectrum is dominated by a dense thicket of strong absorption lines, including numerous OII transitions. We conclude it is likely an unusual hot, hydrogen-poor post-AGB star, possibly in transition from [WC] to white dwarf. Even lacking a complete spectroscopic program, we can infer that late [WC] stars do not dominate the central stars of LMC planetary nebulae, and that the detected CII emitters are largely of an old population.
2842. CIII] emission in near & far star-forming galaxies
ID:
ivo://CDS.VizieR/J/ApJ/814/L6
Title:
CIII] emission in near & far star-forming galaxies
Short Name:
J/ApJ/814/L6
Date:
21 Oct 2021
Publisher:
CDS
Description:
We measure [C III] 1907, C III] 1909{AA} emission lines in 11 gravitationally lensed star-forming galaxies at z~1.6-3, finding much lower equivalent widths than previously reported for fainter lensed galaxies. While it is not yet clear what causes some galaxies to be strong C III] emitters, C III] emission is not a universal property of distant star-forming galaxies. We also examine C III] emission in 46 star-forming galaxies in the local universe, using archival spectra from GHRS, FOS, and STIS on HST and IUE. Twenty percent of these local galaxies show strong C III] emission, with equivalent widths <-5{AA}. Three nearby galaxies show C III] emission equivalent widths as large as the most extreme emitters yet observed in the distant universe; all three are Wolf-Rayet galaxies. At all redshifts, strong C III] emission may pick out low-metallicity galaxies experiencing intense bursts of star formation. Such local C iii] emitters may shed light on the conditions of star formation in certain extreme high-redshift galaxies.
2843. [CII], [OI] and [OIII] line emission from z~6 gal.
ID:
ivo://CDS.VizieR/J/ApJ/846/105
Title:
[CII], [OI] and [OIII] line emission from z~6 gal.
Short Name:
J/ApJ/846/105
Date:
21 Oct 2021
Publisher:
CDS
Description:
Of the almost 40 star-forming galaxies at z>~5 (not counting quasi-stellar objects) observed in [CII] to date, nearly half are either very faint in [CII] or not detected at all, and fall well below expectations based on locally derived relations between star formation rate and [CII] luminosity. This has raised questions as to how reliable [CII] is as a tracer of star formation activity at these epochs and how factors such as metallicity might affect the [CII] emission. Combining cosmological zoom simulations of galaxies with SIGAME (SImulator of GAlaxy Millimeter/submillimeter Emission), we modeled the multiphased interstellar medium (ISM) and its emission in [CII], as well as in [OI] and [OIII], from 30 main-sequence galaxies at z~6 with star formation rates ~3-23M_{sun}_/yr, stellar masses ~(0.7-8)x10^9^M_{sun}_, and metallicities ~(0.1-0.4)xZ_{sun}_. The simulations are able to reproduce the aforementioned [CII] faintness of some normal star-forming galaxy sources at z>=5. In terms of [OI] and [OIII], very few observations are available at z>~5, but our simulations match two of the three existing z>~5 detections of [OIII] and are furthermore roughly consistent with the [OI] and [OIII] luminosity relations with star formation rate observed for local starburst galaxies. We find that the [CII] emission is dominated by the diffuse ionized gas phase and molecular clouds, which on average contribute ~66% and ~27%, respectively. The molecular gas, which constitutes only ~10% of the total gas mass, is thus a more efficient emitter of [CII] than the ionized gas, which makes up ~85% of the total gas mass. A principal component analysis shows that the [CII] luminosity correlates with the star formation activity of a galaxy as well as its average metallicity. The low metallicities of our simulations together with their low molecular gas mass fractions can account for their [CII] faintness, and we suggest that these factors may also be responsible for the [CII]-faint normal galaxies observed at these early epochs.
2844. [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}_.
2845. [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.
2846. 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.
2847. 4C 41.17 IRAM/NOEMA data cubes
ID:
ivo://CDS.VizieR/J/A+A/639/L13
Title:
4C 41.17 IRAM/NOEMA data cubes
Short Name:
J/A+A/639/L13
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present new, spatially resolved [CI]1-0, [CI]2-1, CO(7-6), and dust continuum observations of 4C 41.17 at z=3.8. This is one of the best-studied radio galaxies in this epoch and is arguably the best candidate of jet-triggered star formation at high redshift currently known in the literature. 4C 41.17 shows a narrow ridge of dust continuum extending over 15kpc near the radio jet axis. Line emission is found within the galaxy in the region with signatures of positive feedback. Using the [CI]1-0 line as a molecular gas tracer, and multifrequency observations of the far-infrared dust heated by star formation, we find a total gas mass of 7.6x10^10^M_{sun}_, which is somewhat greater than that previously found from CO(4-3). The gas mass surface density of 10^3^M_{sun}_/yr/pc^2^ and the star formation rate surface density of 10M_{sun}_/yr/kpc^2^ were derived over the 12 kpc8 kpc area, where signatures of positive feedback have previously been found. These densities are comparable to those in other populations of massive, dusty star-forming galaxies in this redshift range, suggesting that the jet does not currently enhance the efficiency with which stars form from the gas. This is consistent with expectations from simulations, whereby radio jets may facilitate the onset of star formation in galaxies without boosting its efficiency over longer timescales, in particular after the jet has broken out of the interstellar medium, as is the case in 4C 41.17. The release includes Gaussian line fits to the [CI]1-0, [CI]2-1, and CO(7-6) emission lines in the radio galaxy 4C 41.17 at z=3.8, as well as the interferometric data cubes.
2848. Circular polarization images at 15GHz of AGN jets
ID:
ivo://CDS.VizieR/J/AJ/131/1262
Title:
Circular polarization images at 15GHz of AGN jets
Short Name:
J/AJ/131/1262
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report first-epoch circular polarization results for 133 active galactic nuclei in the MOJAVE (Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments) program to monitor the structure and polarization of a flux-limited sample of extragalactic radio jets with the VLBA at 15GHz. We found strong circular polarization (0.3%) in approximately 15% of our sample. The circular polarization was usually associated with jet cores; however, we did find a few strong jet components to be circularly polarized.
2849. Circular polarization in pulsars
ID:
ivo://CDS.VizieR/J/other/ChJAA/6.237
Title:
Circular polarization in pulsars
Short Name:
J/other/ChJAA/6.
Date:
21 Oct 2021
Publisher:
CDS
Description:
We update the systematic studies of circular polarization in integrated pulse profiles by Han et al. (1998MNRAS.300..373H). Data of circular polarization profiles are compiled. Sense reversals can occur in core or cone components, or near the intersection between components. The correlation between the sense of circular polarization and the sense of position angle variation for conal-double pulsars is confirmed with a much large database. Circular polarization of some pulsars has clear changes with frequency. Circular polarization of millisecond pulsars is marginally different from that of normal pulsars.
2850. Circular polarization of starlight
ID:
ivo://CDS.VizieR/J/other/Ap/47.305
Title:
Circular polarization of starlight
Short Name:
J/other/Ap/47.30
Date:
21 Oct 2021
Publisher:
CDS
Description:
Of the 7500 stars cited in the Catalog of starlight polarization (Cat. <II/34>), those which satisfy the condition P<=0.3% and A_V_>=0.5mag are selected. It is presumed that the selected stars (n=216) have circularly polarized light.

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