- ID:
- ivo://CDS.VizieR/J/AJ/156/148
- Title:
- Multiwavelength photometry of RCB stars
- Short Name:
- J/AJ/156/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of extended, cold dust envelopes surrounding R Coronae Borealis (RCB) stars began with their discovery by the Infrared Astronomical Satellite. RCB stars are carbon-rich supergiants characterized by their extreme hydrogen deficiency and their irregular and spectacular declines in brightness (up to 9 mag). We have analyzed new and archival Spitzer Space Telescope and Herschel Space Observatory data of the envelopes of seven RCB stars to examine the morphology and investigate the origin of these dusty shells. Herschel, in particular, has revealed the first-ever bow shock associated with an RCB star with its observations of SU Tauri. These data have allowed the assembly of the most comprehensive spectral energy distributions (SEDs) of these stars with multiwavelength data from the ultraviolet to the submillimeter. Radiative transfer modeling of the SEDs implies that the RCB stars in this sample are surrounded by an inner warm (up to 1200 K) and an outer cold (up to 200 K) envelope. The outer shells are suggested to contain up to 10^-3^ M_{sun}_ of dust and have existed for up to 10^5^ years depending on the expansion rate of the dust. This age limit indicates that these structures have most likely been formed during the RCB phase.
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- ID:
- ivo://CDS.VizieR/J/ApJ/761/114
- Title:
- Multi-wavelength study of clusters of galaxies. II.
- Short Name:
- J/ApJ/761/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxy clusters provide powerful laboratories for the study of galaxy evolution, particularly the origin of correlations of morphology and star formation rate (SFR) with density. We construct visible to MIR spectral energy distributions of galaxies in eight low-redshift (z<0.3) clusters and use them to measure stellar masses and SFRs as a function of environment. A partial correlation analysis indicates that the SFRs of star-forming galaxies (SFGs) depend strongly on M_*_ (>99% confidence) with no dependence on R/R_200_ or projected local density at fixed mass. A merged sample of galaxies from the five best measured clusters shows <SFR>{prop.to}(R/R_200_)^1.1+/-0.3^ for galaxies with R/R_200_<=0.4. A decline in the fraction of SFGs toward the cluster center contributes most of this effect, but it is accompanied by a reduction in <SFR> for SFGs with R<=0.1R_200_. The increase in the fraction of SFGs toward larger R/R_200_ and the isolation of SFGs with reduced SFRs near the cluster center are consistent with the truncation of star formation by ram-pressure stripping, as is the tendency for more massive SFGs to have higher SFRs. We conclude that stripping is more likely than slower processes to drive the properties of SFGs with R<0.4R_200_ in clusters. We also find that galaxies near the cluster center are more massive than galaxies farther out in the cluster at ~3.5{sigma}, which suggests that dynamical relaxation significantly impacts the distribution of cluster galaxies as the clusters evolve.
- ID:
- ivo://CDS.VizieR/J/MNRAS/461/2502
- Title:
- Multiwavelength study of HII region S311
- Short Name:
- J/MNRAS/461/2502
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiwavelength investigation of the young stellar population and star formation activities around the HII region Sharpless 311. Using our deep near-infrared observations and archival Spitzer-IRAC observations, we have detected a total of 125 young stellar objects (YSOs) in an area of ~86 arcmin^2^. The YSO sample includes eight Class I and 117 Class II candidate YSOs. The mass completeness of the identified YSO sample is estimated to be 1.0M_{sun}_. The ages and masses of the majority of the candidate YSOs are estimated to be in the range ~0.1-5Myr and ~0.3-6M_{sun}_, respectively. The 8um image of S311 displays an approximately spherical cavity around the ionizing source, which was possibly created by the expansion of the H ii region. The spatial distribution of the candidate YSOs reveals that a significant number of them are distributed systematically along the 8-{mu}m emission with a majority clustered around the eastern border of the HII region. Four clumps/compact HII regions are detected in the radio continuum observations at 1280MHz, which may have been formed during the expansion of the HII region. The estimated dynamical age of the region, main-sequence lifetime of the ionizing source, the spatial distribution and ages of the candidate YSOs indicate triggered star formation in the complex.
- ID:
- ivo://CDS.VizieR/J/MNRAS/391/1279
- Title:
- Multiwavelength study of NGC 7419
- Short Name:
- J/MNRAS/391/1279
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using new UBVRI H{alpha} CCD photometric observations and the archival infrared and X-ray data, we have carried out a multiwavelength study of a Perseus arm young open star cluster NGC 7419. Using XMM-Newton observations, we found several X-ray sources in the cluster region but none of the Herbig Ae/Be stars is detected in X-rays.
- ID:
- ivo://CDS.VizieR/J/PASJ/64/107
- Title:
- Multiwavelength study of NGC 281 complex
- Short Name:
- J/PASJ/64/107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a multiwavelength study of the NGC 281 complex, which contains the young cluster IC 1590 at the center, using deep wide-field optical UBVIc photometry, slitless spectroscopy along with archival data sets in the near-infrared (NIR) and X-ray regions.
- ID:
- ivo://CDS.VizieR/J/ApJ/789/81
- Title:
- Multiwavelength survey of HII regions in NGC 300
- Short Name:
- J/ApJ/789/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a galaxy-wide study of molecular gas and star formation in a sample of 76 H II regions in the nearby spiral galaxy NGC 300. We have measured the molecular gas at 250pc scales using pointed CO(J=2-1) observations with the Atacama Pathfinder Experiment telescope. We detect CO in 42 of our targets, deriving molecular gas masses ranging from our sensitivity limit of ~10^5^M_{sun}_ to 7x10^5^M_{sun}_. We find a clear decline in the CO detection rate with galactocentric distance, which we attribute primarily to the decreasing radial metallicity gradient in NGC 300. We combine Galaxy Evolution Explorer far-ultraviolet, Spitzer 24{mu}m, and H{alpha} narrowband imaging to measure the star formation activity in our sample. We have developed a new direct modeling approach for computing star formation rates (SFRs) that utilizes these data and population synthesis models to derive the masses and ages of the young stellar clusters associated with each of our H II region targets. We find a characteristic gas depletion time of 230Myr at 250pc scales in NGC 300, more similar to the results obtained for Milky Way giant molecular clouds than the longer (>2Gyr) global depletion times derived for entire galaxies and kiloparsec-sized regions within them. This difference is partially due to the fact that our study accounts for only the gas and stars within the youngest star-forming regions. We also note a large scatter in the NGC 300 SFR-molecular gas mass scaling relation that is furthermore consistent with the Milky Way cloud results. This scatter likely represents real differences in giant molecular cloud physical properties such as the dense gas fraction.
- ID:
- ivo://CDS.VizieR/J/ApJ/634/L1
- Title:
- 16{mu}m sources in the NOAO Bootes field
- Short Name:
- J/ApJ/634/L1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the 16{mu}m peak-up imager on the Infrared Spectrograph (IRS) on Spitzer, we present a serendipitous survey of 0.0392{deg}^2^ within the area of the NOAO Deep Wide-Field Survey in Bootes. Combining our results with the available Multiband Imaging Photometer for Spitzer (MIPS) 24{mu}m survey of this area, we produce a catalog of 150 16{mu}m sources brighter than 0.18mJy (3{sigma}) for which we derive measures or limits on the 16{mu}m/24{mu}m colors. Such colors are especially useful in determining redshifts for sources whose mid-infrared spectra contain strong emission or absorption features that characterize these colors as a function of redshift.
- ID:
- ivo://CDS.VizieR/J/AJ/121/2673
- Title:
- 3{mu}m survey of the Chamaeleon I dark cloud
- Short Name:
- J/AJ/121/2673
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe an L-band photometric survey of ~0.5deg^2^ of the Chamaeleon I dark cloud. The survey has a completeness limit of L<11.0. Our survey detects 124 sources, including all known pre-main-sequence stars with L<=11. The fraction of sources with near-IR excess emission is 58%+/-4% for K=9-11. Cha I sources have bluer H-K and K-L colors than pre-main-sequence stars in Taurus-Auriga. These sources also have a strong correlation between EW(H{alpha} and K-L. Stars with K-L<=0.6 have weak H{alpha} emission; stars with K-L>=0.6 have strong H{alpha]mission. Because many Cha I sources are heavily reddened, this division between weak emission T Tauri stars and classical T Tauri stars occurs at a redder K-L than in Taurus-Auriga. We acquired L-band photometry of Cha I sources and standard stars using the South Pole Infrared Explorer (SPIREX) during the 1999 March-October observing season. The SPIREX 60cm telescope developed by CARA for observations at the South Pole was equipped with the NOAO/KPNO Abu infrared camera, which includes a first generation 1024x1024 InSb detector array.
- ID:
- ivo://CDS.VizieR/J/AJ/134/1103
- Title:
- MUSYC deep near-infrared imaging
- Short Name:
- J/AJ/134/1103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep near-infrared JHK imaging of four 10x10 fields. The observations were carried out as part of the Multiwavelength Survey by Yale-Chile (MUSYC) with ISPI on the CTIO 4m telescope. The typical point-source limiting depths are J~22.5, H~21.5, and K~21 (5{sigma}; Vega). The effective seeing in the final images is 1.0". We combine these data with MUSYC UBVRIz imaging to create K-selected catalogs that are unique for their uniform size, depth, filter coverage, and image quality.
- ID:
- ivo://CDS.VizieR/J/ApJS/189/270
- Title:
- MUSYC optical imaging in ECDF-S
- Short Name:
- J/ApJS/189/270
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep optical 18-medium-band photometry from the Subaru telescope over the ~30'x30' Extended Chandra Deep Field-South, as part of the Multiwavelength Survey by Yale-Chile (MUSYC). This field has a wealth of ground- and space-based ancillary data, and contains the GOODS-South field and the Hubble Ultra Deep Field. We combine the Subaru imaging with existing UBVRIzJHK and Spitzer IRAC images to create a uniform catalog. Detecting sources in the MUSYC "BVR" image we find ~40,000 galaxies with R_AB_<25.3, the median 5{sigma} limit of the 18 medium bands. Photometric redshifts are determined using the EAzY code and compared to ~2000 spectroscopic redshifts in this field. The medium-band filters provide very accurate redshifts for the (bright) subset of galaxies with spectroscopic redshifts, particularly at 0.1<z<1.2 and at z~>3.5. For 0.1<z<1.2, we find a 1{sigma} scatter in {DELTA}z/(1+z) of 0.007, similar to results obtained with a similar filter set in the COSMOS field. As a demonstration of the data quality, we show that the red sequence and blue cloud can be cleanly identified in rest-frame color-magnitude diagrams at 0.1<z<1.2. We find that ~20% of the red sequence galaxies show evidence of dust emission at longer rest-frame wavelengths. The reduced images, photometric catalog, and photometric redshifts are provided through the public MUSYC Web site (http://www.astro.yale.edu/MUSYC/).
