Search

Start Over Capability Type Simple Cone Search
3271. CO obs. of molecular outflows in the Cygnus complex
ID:
ivo://CDS.VizieR/J/ApJS/248/15
Title:
CO obs. of molecular outflows in the Cygnus complex
Short Name:
J/ApJS/248/15
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a survey of molecular outflows across the dark cloud complex in the Cygnus region, based on a 46.75deg^2^ field of CO isotopologue data from the Milky Way Imaging Scroll Painting (MWISP) survey. A supervised machine-learning algorithm, the support vector machine, is introduced to accelerate our visual assessment of outflow features in the data cube of ^12^CO and ^13^CO J=1-0 emission. A total of 130 outflow candidates are identified, 77 of which show bipolar structures and 118 are new detections. Spatially, these outflows are located inside dense molecular clouds, and some of them are found in clusters or in elongated linear structures tracing the underlying gas filament morphology. Along the line of sight, 97, 31, and 2 candidates reside in the Local, Perseus, and Outer Arms, respectively. Young stellar objects as outflow drivers are found near most outflows, while 36 candidates show no associated source. The clusters of outflows that we detect are inhomogeneous in their properties; nevertheless, we show that the outflows cannot inject turbulent energy on cloud scales. Instead, at best, they are restricted to affecting the so-called "clump" and "core" scales, and only on short (~0.3Myr) estimated timescales. Combined with outflow samples in the literature, our work shows a tight outflow mass-size correlation.
3272. CO obs. of Planck Galactic cold clumps
ID:
ivo://CDS.VizieR/J/ApJS/247/29
Title:
CO obs. of Planck Galactic cold clumps
Short Name:
J/ApJS/247/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
Sixty-five Planck Galactic cold clumps (PGCCs) from the first quadrant (IQuad) and 39 from the anticenter direction region (ACent) were observed in ^12^CO, ^13^CO, and C^18^O J=1-0 lines using the 13.7m telescope of the Purple Mountain Observatory. All the targets were detected in all three lines, except for 12 IQuad and 8 ACent PGCCs without C^18^O detection. Seventy-six and 49 velocity components were obtained in IQuad and ACent respectively; 146 cores were extracted from 76 IQuad clumps and 100 cores from 49 ACent clumps. The average Tex of IQuad cores and ACent cores is 12.4K and 12.1K, respectively. The average line widths of ^13^CO of IQuad cores and ACent cores are 1.55km/s and 1.77km/s, respectively. Among the detected cores, 24 in IQuad and 13 in ACent have asymmetric line profiles. The small blue excesses, ~0.03 in IQuad and 0.01 in ACent, indicate that star formation is not active in these PGCC cores. Power-law fittings of the core mass function to the high-mass end give indices of -0.57 in IQuad and -1.02 in ACent, which are flatter than the slope of the initial mass function given by Salpeter. The large turnover masses of 28M_{sun}_ for IQuad cores and 77M_{sun}_ for ACent cores suggest low star formation efficiencies in PGCCs. The correlation between virial mass and gas mass indicates that most PGCC cores in both regions are not likely pressure-confined.
3273. CO obs. of the outer arm in the 2nd quadrant
ID:
ivo://CDS.VizieR/J/ApJS/224/7
Title:
CO obs. of the outer arm in the 2nd quadrant
Short Name:
J/ApJS/224/7
Date:
21 Oct 2021
Publisher:
CDS
Description:
The lack of arm tracers, especially remote tracers, is one of the most difficult problems preventing us from studying the structure of the Milky Way. Fortunately, with its high-sensitivity CO survey, the Milky Way Imaging Scroll Painting (MWISP) project offers such an opportunity. Since completing about one-third of its mission, an area of l=[100,150]{deg}, b=[-3,5]{deg} has nearly been covered. The Outer arm of the Milky Way first clearly revealed its shape in the second galactic quadrant in the form of molecular gas --this is the first time that the Outer arm has been reported in such a large-scale mapping of molecular gas. Using the 115GHz ^12^CO(1-0) data of MWISP at the LSR velocity ~[-100,-60]km/s and in the area mentioned above, we have detected 481 molecular clouds in total, and among them 332 (about 69%) are newly detected and 457 probably belong to the Outer arm. The total mass of the detected Outer arm clouds is ~3.1x10^6^M_{sun}__. Assuming that the spiral arm is a logarithmic spiral, the pitch angle is fitted as ~13.1{deg}. Besides combining both the CO data from MWISP and the 21cm HI data from the Canadian Galactic Plane Survey (CGPS), the gas distribution, warp, and thickness of the Outer arm are also studied.
3274. Cool carbon stars in the halo and Fornax dSph
ID:
ivo://CDS.VizieR/J/A+A/562/A24
Title:
Cool carbon stars in the halo and Fornax dSph
Short Name:
J/A+A/562/A24
Date:
21 Oct 2021
Publisher:
CDS
Description:
The population of cool carbon (C) stars located far from the galactic plane is probably made of debris of small galaxies such as the Sagittarius dwarf spheroidal galaxy (Sgr), which are disrupted by the gravitational field of the Galaxy. We aim to know this population better through spectroscopy, 2MASS photometric colours, and variability data. When possible, we compared the halo results to C star populations in the Fornax dwarf spheroidal galaxy, Sgr, and the solar neighbourhood. We first present a few new discoveries of C stars in the halo and in Fornax. The number of spectra of halo C stars is now 125. Forty percent show H{alpha} in emission. The narrow location in the JHK diagram of the halo C stars is found to differ from that of similar C stars in the above galaxies. The light curves of the Catalina and LINEAR variability databases were exploited to derive the pulsation periods of 66 halo C stars. A few supplementary periods were obtained with the TAROT telescopes. We confirm that the period distribution of the halo strongly resembles that of Fornax, and we found that it is very different from the C stars in the solar neighbourhood. There is a larger proportion of short-period Mira/SRa variables in the halo than in Sgr, but the survey for C stars in this dwarf galaxy is not complete, and the study of their variability needs to be continued to investigate the link between Sgr and the cool halo C stars.
3275. Cool-core clusters with Chandra obs.
ID:
ivo://CDS.VizieR/J/ApJ/843/76
Title:
Cool-core clusters with Chandra obs.
Short Name:
J/ApJ/843/76
Date:
21 Oct 2021
Publisher:
CDS
Description:
We derive and compare the fractions of cool-core clusters in the Planck Early Sunyaev-Zel'dovich sample of 164 clusters with z<=0.35 and in a flux- limited X-ray sample of 100 clusters with z<=0.30, using Chandra observations. We use four metrics to identify cool-core clusters: (1) the concentration parameter, which is the ratio of the integrated emissivity profile within 0.15 r_500_ to that within r_500_; (2) the ratio of the integrated emissivity profile within 40kpc to that within 400kpc; (3) the cuspiness of the gas density profile, which is the negative of the logarithmic derivative of the gas density with respect to the radius, measured at 0.04 r_500_; and (4) the central gas density, measured at 0.01 r_500_. We find that the sample of X-ray-selected clusters, as characterized by each of these metrics, contains a significantly larger fraction of cool-core clusters compared to the sample of SZ-selected clusters (44%+/-7% versus 28%+/-4% using the concentration parameter in the 0.15-1.0 r_500_ range, 61%+/-8% versus 36%+/-5% using the concentration parameter in the 40-400 kpc range, 64%+/-8% versus 38%+/-5% using the cuspiness, and 53%+/-7% versus 39+/-5% using the central gas density). Qualitatively, cool-core clusters are more X-ray luminous at fixed mass. Hence, our X-ray, flux-limited sample, compared to the approximately mass-limited SZ sample, is overrepresented with cool-core clusters. We describe a simple quantitative model that uses the excess luminosity of cool-core clusters compared to non-cool-core clusters at fixed mass to successfully predict the observed fraction of cool-core clusters in X-ray-selected samples.
3276. 86 cool dwarfs observed during K2 Campaigns 1-17
ID:
ivo://CDS.VizieR/J/AJ/158/87
Title:
86 cool dwarfs observed during K2 Campaigns 1-17
Short Name:
J/AJ/158/87
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present revised stellar properties for 172 K2 target stars that were identified as possible hosts of transiting planets during Campaigns 1-17. Using medium-resolution near-infrared spectra acquired with the NASA Infrared Telescope Facility/SpeX and Palomar/TripleSpec, we found that 86 of our targets were bona fide cool dwarfs, 74 were hotter dwarfs, and 12 were giants. Combining our spectroscopic metallicities with Gaia parallaxes and archival photometry, we derived photometric stellar parameters and compared them to our spectroscopic estimates. Although our spectroscopic and photometric radius and temperature estimates are consistent, our photometric mass estimates are systematically {Delta}M_*_=0.11 M_{sun}_ (34%) higher than our spectroscopic mass estimates for the least massive stars (M_*,phot_<0.4 M_{sun}_). Adopting the photometric parameters and comparing our results to parameters reported in the Ecliptic Plane Input Catalog, our revised stellar radii are {Delta}R_*_=0.15 R_{sun}_ (40%) larger, and our revised stellar effective temperatures are roughly {Delta}T_eff_=65 K cooler. Correctly determining the properties of K2 target stars is essential for characterizing any associated planet candidates, estimating the planet search sensitivity, and calculating planet occurrence rates. Even though Gaia parallaxes have increased the power of photometric surveys, spectroscopic characterization remains essential for determining stellar metallicities and investigating correlations between stellar metallicity and planetary properties.
3277. Cool DZ white dwarfs. I.
ID:
ivo://CDS.VizieR/J/MNRAS/467/4970
Title:
Cool DZ white dwarfs. I.
Short Name:
J/MNRAS/467/4970
Date:
21 Oct 2021
Publisher:
CDS
Description:
White dwarfs with metal lines in their spectra act as signposts for post-main-sequence planetary systems. Searching the Sloan Digital Sky Survey (SDSS) Data Release 12, we have identified 231 cool (<9000K) DZ white dwarfs with strong metal absorption, extending the DZ cooling sequence to both higher metal abundances and lower temperatures, and hence longer cooling ages. Of these 231 systems, 104 are previously unknown white dwarfs. Compared with previous work, our spectral fitting uses improved model atmospheres with updated line profiles and line-lists, which we use to derive effective temperatures and abundances for up to eight elements. We also determine spectroscopic distances to our sample, identifying two halo members with tangential space velocities >300km/s. The implications of our results on remnant planetary systems are to be discussed in a separate paper.
3278. Cool evolved stars in SAGE-SMC and SAGE-LMC
ID:
ivo://CDS.VizieR/J/AJ/142/103
Title:
Cool evolved stars in SAGE-SMC and SAGE-LMC
Short Name:
J/AJ/142/103
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the infrared (IR) properties of cool, evolved stars in the Small Magellanic Cloud (SMC), including the red giant branch (RGB) stars and the dust-producing red supergiant (RSG) and asymptotic giant branch (AGB) stars using observations from the Spitzer Space Telescope Legacy program entitled "Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity SMC", or SAGE-SMC. The survey includes, for the first time, full spatial coverage of the SMC bar, wing, and tail regions at IR wavelengths (3.6-160um). We identify evolved stars using a combination of near-IR and mid-IR photometry and point out a new feature in the mid-IR color-magnitude diagram that may be due to particularly dusty O-rich AGB stars. We find that the RSG and AGB stars each contribute ~20% of the global SMC flux (extended + point-source) at 3.6um, which emphasizes the importance of both stellar types to the integrated flux of distant metal-poor galaxies.
3279. Cool, evolved stars PACS and SPIRE spectroscopy
ID:
ivo://CDS.VizieR/J/A+A/618/A143
Title:
Cool, evolved stars PACS and SPIRE spectroscopy
Short Name:
J/A+A/618/A143
Date:
21 Oct 2021
Publisher:
CDS
Description:
At the end of their lives AGB stars are prolific producers of dust and gas. The details of this mass-loss process are still not understood very well. Herschel PACS and SPIRE spectra which cover the wavelength range from ~55 to 670um almost continuously, offer a unique way of investigating properties of AGB stars in general and the mass-loss process in particular as this is the wavelength region where dust emission is prominent and molecules have many emission lines. We present the community with a catalogue of AGB stars and red supergiants (RSGs) with PACS and/or SPIRE spectra reduced according to the current state of the art. The Herschel Interactive Processing Environment (HIPE) software with the latest calibration is used to process the available PACS and SPIRE spectra of 40 evolved stars. The SPIRE spectra of some objects close to the Galactic plane require special treatment because of the weaker fluxes in combination with the strong and complex background emission at those wavelengths. The spectra are convolved with the response curves of the PACS and SPIRE bolometers and compared to the fluxes measured in imaging data of these sources. Custom software is used to identify lines in the spectra, and to determine the central wavelengths and line intensities. Standard molecular line databases are used to associate the observed lines. Because of the limited spectral resolution of the PACS and SPIRE spectrometers (~1500), several known lines are typically potential counterparts to any observed line. To help identifications in follow-up studies the relative contributions in line intensity of the potential counterpart lines are listed for three characteristic temperatures based on local thermodynamic equilibrium (LTE) calculations and assuming optically thin emission. The following data products are released: the reduced spectra, the lines that are measured in the spectra with wavelength, intensity, potential identifications, and the continuum spectra, i.e. the full spectra with all identified lines removed. As simple examples of how this data can be used in future studies we have fitted the continuum spectra with three power laws (two wavelength regimes covering PACS, and one covering SPIRE) and find that the few OH/IR stars seem to have significantly steeper slopes than the other oxygen- and carbon-rich objects in the sample, possibly related to a recent increase in mass-loss rate. As another example we constructed rotational diagrams for CO (and HCN for the carbon stars) and fitted a two-component model to derive rotational temperatures.
3280. Cool Galactic Carbon Stars, 2nd Edition
ID:
ivo://CDS.VizieR/III/156
Title:
Cool Galactic Carbon Stars, 2nd Edition
Short Name:
III/156
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalog is intended to list all 5987 cool carbon stars having known positions of at least roughly the precision of The Henry Draper Catalogue. Cool carbon stars are defined as stars whose spectra at low dispersion (say a resolution no better than 1-2 angstroms) are known to show bands of the Swan system of the C2 molecule; or, if the spectral region of the Swan system is inadequately observed, they show the red or infrared bands of CN in strength adequate to infer that the Swan bands almost certainly would be seen if their presence could be tested. The closing date for literature search was 1989 June 30, defined by literature received in the author's library by that date. The catalog includes equatorial coordinates (B1900.0); photographic, visual, and infrared magnitudes; spectral types, galactic coordinates, and cross identifications to various other designation systems.

Limit your search

more »

more »

more »

more »

  • 218,084
  • 111

more »

more »