- ID:
- ivo://CDS.VizieR/J/A+A/629/A91
- Title:
- A source catalog for the SMC
- Short Name:
- J/A+A/629/A91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a clean, magnitude-limited (IRAC1 or WISE1 <=15.0mag) multiwavelength source catalog for the Small Magellanic Cloud (SMC) with 45466 targets in total, with the purpose of building an anchor for future studies, especially for the massive star populations at low-metallicity. The catalog contains data in 50 different bands including 21 optical and 29 infrared bands, retrieved from SEIP, VMC, IRSF, AKARI, HERITAGE, Gaia, SkyMapper, NSC, Massey (2002, Cat. II/236), and GALEX, ranging from the ultraviolet to the far-infrared. Additionally, radial velocities and spectral classifications were collected from the literature, and infrared and optical variability statistics were retrieved from WISE, SAGE-Var, VMC, IRSF, Gaia, NSC, and OGLE. The catalog was essentially built upon a 1" crossmatching and a 3" deblending between the Spitzer Enhanced Imaging Products (SEIP) source list and Gaia Data Release 2 (DR2) photometric data. Further constraints on the proper motions and parallaxes from Gaia DR2 allowed us to remove the foreground contamination. We estimate that about 99.5% of the targets in our catalog are most likely genuine members of the SMC. Using the evolutionary tracks and synthetic photometry from MESA Isochrones & Stellar Tracks and the theoretical J-K_S_ color cuts, we identified 1405 red supergiant (RSG), 217 yellow supergiant, and 1,369 blue supergiant candidates in the SMC in five different color-magnitude diagrams (CMDs), where attention should also be paid to the incompleteness of our sample. We ranked the candidates based on the intersection of different CMDs. A comparison between the models and observational data shows that the lower limit of initial mass for the RSG population may be as low as 7 or even 6M_{sun}_ and that the RSG is well separated from the asymptotic giant branch (AGB) population even at faint magnitude, making RSGs a unique population connecting the evolved massive and intermediate stars, since stars with initial mass around 6 to 8$M_{sun}_ are thought to go through a second dredge-up to become AGB stars. We encourage the interested reader to further exploit the potential of our catalog.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/705/68
- Title:
- A Spitzer ultradeep survey (SUUSS)
- Short Name:
- J/ApJ/705/68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out an unbiased, spectroscopic survey using the low-resolution module of the infrared spectrograph (IRS) onboard Spitzer targeting two 2.6 square arcminute regions in the GOODS-North field. The IRS was used in a spectral mapping mode with 5hr of effective integration time per pixel. One region was covered between 14 and 21um and the other between 20 and 35um. We extracted spectra for 45 sources. About 84% of the sources have reported detections by GOODS at 24um, with a median f_{nu}_(24um)~100uJy. All but one source are detected in all four IRAC bands, 3.6 to 8um. We use a new cross-correlation technique to measure redshifts and estimate IRS spectral types; this was successful for ~60% of the spectra. Fourteen sources show significant polycyclic aromatic hydrocarbon emission, four mostly SiO absorption, eight present mixed spectral signatures (low PAH and/or SiO) and two show a single line in emission. For the remaining 17, no spectral features were detected. Redshifts range from z~0.2 to z~2.2, with a median of 1. IR luminosities are roughly estimated from 24um flux densities, and have median values of 2.2x10^11^L_{sun}_ and 7.5x10^11^L_{sun}_ at z~1 and z~2, respectively. This sample has fewer active galactic nuclei than previous faint samples observed with the IRS, which we attribute to the fainter luminosities reached here.
- ID:
- ivo://CDS.VizieR/J/A+A/284/233
- Title:
- Association of HII regions and IRAS PSC sources
- Short Name:
- J/A+A/284/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/PASJ/63/S1
- Title:
- Atlas and catalog of dark clouds based on 2MASS
- Short Name:
- J/PASJ/63/S1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents an atlas and catalog of dark clouds derived based on the 2 Micron All Sky Survey Point Source Catalog (2MASS PSC). Color excess maps of E(J-H) and E(H-K_S_) as well as extinction maps of A_J_, A_H_, and A_K_S_ covering all of the sky have been produced at the 1' grid with a changing angular resolution (~1'-12'), depending on the regions in the sky. Maps drawn at the lower 15' grid with a fixed 1{deg} resolution were also derived for various sets of threshold magnitudes in the J, H, and K_S_ bands to estimate the background star colors and star densities needed to derive the color excess and extinction maps. The maps obtained in this work are presented on various scales in a series of figures that can be used as an atlas of dark clouds for general research purposes. On the basis of the E(J-H) and A_J_ maps drawn at the 1' grid, we have carried out a systematic survey for dark clouds all over the sky. In total, we identified 7614 dark clouds, and measured the coordinates, extents, and A_V_ values for each of them. We also searched for their counterparts in a previously published catalog of dark clouds based on the optical photographic plates DSS (Dobashi et al., 2005PASJ...57S...1D, Cat. VII/244). These cloud parameters, including the information of the counterparts, are compiled into a new catalog of dark clouds.
- ID:
- ivo://CDS.VizieR/J/ApJ/824/29
- Title:
- ATLASGAL clumps with IRAS flux and MALT90 data
- Short Name:
- J/ApJ/824/29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a survey of 65 galaxies, Gao & Solomon (2004ApJS..152...63G) found a tight linear relation between the infrared luminosity (L_IR_, a proxy for the star formation rate) and the HCN(1-0) luminosity (L_HCN_). Wu et al. (2005ApJ...635L.173W) found that this relation extends from these galaxies to the much less luminous Galactic molecular high-mass star-forming clumps (~1pc scales), and posited that there exists a characteristic ratio L_IR_/L_HCN_ for high-mass star-forming clumps. The Gao-Solomon relation for galaxies could then be explained as a summation of large numbers of high-mass star-forming clumps, resulting in the same L_IR_/L_HCN_ ratio for galaxies. We test this explanation and other possible origins of the Gao-Solomon relation using high-density tracers (including HCN(1-0), N_2_H^+^(1-0), HCO^+^(1-0), HNC(1-0), HC_3_N(10-9), and C_2_H(1-0)) for ~300 Galactic clumps from the Millimetre Astronomy Legacy Team 90GHz (MALT90) survey. The MALT90 data show that the Gao-Solomon relation in galaxies cannot be satisfactorily explained by the blending of large numbers of high-mass clumps in the telescope beam. Not only do the clumps have a large scatter in the L_IR_/L_HCN_ ratio, but also far too many high-mass clumps are required to account for the Galactic IR and HCN luminosities. We suggest that the scatter in the L_IR_/L_HCN_ ratio converges to the scatter of the Gao-Solomon relation at some size-scale >~1kpc. We suggest that the Gao-Solomon relation could instead result from of a universal large-scale star formation efficiency, initial mass function, core mass function, and clump mass function.
- ID:
- ivo://CDS.VizieR/J/ApJS/95/1
- Title:
- Atlas of Quasar Energy Distributions
- Short Name:
- J/ApJS/95/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an atlas of the spectral energy distributions (SEDs) of normal, non-blazar, quasars over the whole available range (radio to 10 keV X-rays) of the electromagnetic spectrum. The primary (UVSX) sample includes 47 quasars for which the spectral energy distributions include X-ray spectral indices and UV data. Of these, 29 are radio quiet, and 18 are radio loud. The SEDs are presented both in figures and in tabular form, with additional tabular material published on CD-ROM. Previously unpublished observational data for a second set of quasars excluded from the primary sample are also tabulated. The effects of host galaxy starlight contamination and foreground extinction on the UVSX sample are considered and the sample is used to investigate the range of SED properties. Of course, the properties we derive are influenced strongly by the selection effects induced by quasar discovery techniques. We derive the mean energy distribution (MED) for radio-loud and radio-quiet objects and present the bolometric corrections derived from it. We note, however, that the dispersion about this mean is large (~one decade for both the infrared and ultraviolet components when the MED is normalized at the near-infrared inflection). At least part of the dispersion in the ultraviolet may be due to time variability, but this is unlikely to be important in the infrared. The existence of such a large dispersion indicates that the MED reflects only some of the properties of quasars and so should be used only with caution.
- ID:
- ivo://CDS.VizieR/J/ApJS/158/139
- Title:
- Atlas of warm AGN and starbursts
- Short Name:
- J/ApJS/158/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a set of 180 active galactic nucleus (AGN) candidates based on color selection from the IRAS slow-scan deep observations, with color criteria broadened from the initial Point Source Catalog (Cat. <II/125>) samples so as to include similar objects with redshifts up to z=1 and allowing for two-band detections. Spectroscopic identifications have been obtained for 80 (44%); some additional identifications are secure based on radio detections or optical morphology, although yet unobserved spectroscopically. These spectroscopic identifications include 13 type-1 Seyfert galaxies, 17 type-2 Seyferts, 29 starburst galaxies, 7 LINER systems, and 13 emission-line galaxies so heavily reddened as to remain of ambiguous classification.
- ID:
- ivo://CDS.VizieR/J/ApJ/764/133
- Title:
- Auriga-California giant molecular cloud
- Short Name:
- J/ApJ/764/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have mapped the Auriga/California molecular cloud with the Herschel PACS and SPIRE cameras and the Bolocam 1.1mm camera on the Caltech Submillimeter Observatory with the eventual goal of quantifying the star formation and cloud structure in this giant molecular cloud (GMC) that is comparable in size and mass to the Orion GMC, but which appears to be forming far fewer stars. We have tabulated 60 compact 70/160 {mu}m sources that are likely pre-main-sequence objects and correlated those with Spitzer and WISE mid-IR sources. At 1.1 mm, we find 18 cold, compact sources and discuss their properties. The most important result from this part of our study is that we find a modest number of additional compact young objects beyond those identified at shorter wavelengths with Spitzer.
- ID:
- ivo://CDS.VizieR/J/A+A/497/41
- Title:
- Average Early-type galaxies NIR spectrum
- Short Name:
- J/A+A/497/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Near-infrared (hereafter NIR) data may provide complementary information to the traditional optical population synthesis analysis of unresolved stellar populations because the spectral energy distribution of the galaxies in the 1-2.5um range is dominated by different types of stars than at optical wavelengths. Furthermore, NIR data are less affected by dust absorption and hence could constrain the stellar populations in dust-obscured galaxies. We attempt to develop observational constraints on the stellar populations of unresolved stellar systems in the NIR.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A94
- Title:
- Avg pitch angles & spiral amplitudes in S4G
- Short Name:
- J/A+A/631/A94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spiral galaxies are very common in the local Universe, but their formation, evolution, and interplay with bars remain poorly understood after more than a century of astronomical research on the topic. We use a sample of 391 nearby galaxies from the S4G survey to characterise the winding angle and amplitude of spiral arms as a function of disc properties, such as bar strength, in all kinds of spirals (grand-design, multi-armed, and flocculent). We derived global pitch angles in 3.6um de-projected images from i) average measurements of individual logarithmic spiral segments, and ii) for a subsample of 32 galaxies, from 2-D Fourier analyses. The strength of spirals was quantified from the tangential-to-radial force ratio and from the normalised m=2 Fourier density amplitudes. In galaxies with more than one measured logarithmic segment, the spiral pitch angle varies on average by ~10{deg} between segments, but by up to >=15-20{deg}. The distribution of the global pitch angle versus Hubble type (T) is very similar for barred and non-barred galaxies when 1<=T<=5. Most spiral galaxies (>90%) are barred for T>5. The pitch angle is not correlated with bar strength, and only weakly with spiral strength. The amplitude of spirals is correlated with bar strength (and less tightly, with bar length) for all types of spirals. The mean pitch angle is hardly correlated with the mass of the supermassive black hole (estimated from central stellar velocity dispersion), with central stellar mass concentration, or with shear, questioning previous results in the literature using smaller samples. We do not find observational evidence that spiral arms are driven by stellar bars or by invariant manifolds. Most likely, discs that are prone to the development of strong bars are also reactive to the formation of prominent spirals, explaining the observed coupling between bar and spiral amplitudes.