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- ID:
- ivo://CDS.VizieR/J/AJ/144/101
- Title:
- Multiwavelength data of IRAS 20050+2720 young SFR
- Short Name:
- J/AJ/144/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IRAS 20050+2720 is young star-forming region at a distance of 700pc without apparent high-mass stars. We present results of our multi-wavelength study of IRAS 20050+2720 which includes observations by Chandra and Spitzer, and Two Micron All Sky Survey and UBVRI photometry. In total, about 300 young stellar objects (YSOs) in different evolutionary stages are found. We characterize the distribution of YSOs in this region using a minimum spanning tree analysis. We newly identify a second cluster core, which consists mostly of class II objects, about 10' from the center of the cloud. YSOs of earlier evolutionary stages are more clustered than more evolved objects. The X-ray luminosity function (XLF) of IRAS 20050+2720 is roughly lognormal, but steeper than the XLF of the more massive Orion Nebula complex. IRAS 20050+2720 shows a lower N_H_/A_K_ ratio compared with the diffuse interstellar medium.
- ID:
- ivo://CDS.VizieR/J/AJ/130/1763
- Title:
- 11.7{mu}m point sources in Orion
- Short Name:
- J/AJ/130/1763
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new 11.7{mu}m mosaic image of the inner Orion Nebula obtained with the T-ReCS instrument on Gemini South. The map covers 2.7'x1.6', with a diffraction-limited spatial resolution of 0.35"; it includes the BN/KL region, the Trapezium, and OMC-1 South. Excluding BN/KL, we detect 91 thermal-IR point sources, with 27 known proplyds and over 30 "naked" stars showing no extended structure in Hubble Space Telescope (HST) images.
- 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/MNRAS/452/173
- Title:
- Nearby young stars in Northern hemisphere
- Short Name:
- J/MNRAS/452/173
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a kinematically-unbiased search to identify young, nearby low-mass members of kinematic moving groups (MGs). Objects with both rotation periods shorter than 5 days in the SuperWASP All-Sky Survey and X-ray counterparts in the ROSAT All-Sky Survey were chosen to create a catalog of several thousand rapidly-rotating, X-ray active FGK stars. These objects are expected to be either genuinely young (<200Myr) single stars or tidally-locked spectroscopic binaries. We obtained optical spectra for a sub-sample of 146 stars to determine their ages and kinematics, and in some cases repeat radial velocity (RV) measurements were used to identify binarity. Twenty-six stars are found to have lithium abundances consistent with an age of 200Myr or younger and show no evidence for binarity, and in most cases measurements of Halpha and v sin i support their youthful status. Based on their youth, their radial velocities and estimates of their 3-dimensional kinematics, we find 11 objects that may be members of known MGs, 8 that do not appear associated with any young MG and a further 7 that are close to the kinematics of the recently proposed "Octans-Near" MG, and may be the first members of this MG found in the northern hemisphere. The initial search mechanism was ~18 per cent efficient at identifying likely-single stars younger than 200Myr, of which 80 per cent were early-K spectral types. A more complete survey may result in the detection of new nearby MGs, particularly in the comparatively little sampled northern hemisphere.
- ID:
- ivo://CDS.VizieR/J/A+A/510/A1
- Title:
- Near infrared imaging of cometary globule CG12
- Short Name:
- J/A+A/510/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cometary globule 12 is a relatively little investigated medium- and low mass star forming region 210pc above the Galactic plane. This study sets out to discover the possibly embedded members of the CG 12 stellar cluster, to refine the NIR photometry of the known member stars and to study the star formation activity in CG 12 and its relation to the distribution of molecular gas, dust and mid- to far-infrared emission in the cloud. NIR J, H, and Ks imaging and stellar photometry is used to analyse the stellar content and the structure of CG 12.
- ID:
- ivo://CDS.VizieR/J/A+A/642/L15
- Title:
- Near-infrared spectra for TW Hya
- Short Name:
- J/A+A/642/L15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Volatile molecules are critical to terrestrial planetary habitability, yet they are difficult to observe directly where planets form at the midplanes of protoplanetary disks. It is unclear whether the inner ~1AU of disks are volatile-poor or if this region is resupplied with ice-rich dust from colder disk regions. Dust traps at radial pressure maxima bounding disk gaps can cut off the inner disk from these types of volatile reservoirs. However, the trap retention efficiency and atomic composition of trapped dust have not been measured. We present a new technique to measure the absolute atomic abundances in the gas accreting onto T Tauri stars and infer the bulk atomic composition and distribution of midplane solids that have been retained in the disk around the young star TW Hya. We identify near-infrared atomic line emission from gas-phase material inside the dust sublimation rim of TW Hya. Gaussian decomposition of the strongest H Paschen lines isolates the inner disk hydrogen emission. We measure several key elemental abundances, relative to hydrogen, using a chemical photoionization model and infer dust retention in the disk. With a 1D transport model, we determine approximate radial locations and retention efficiencies of dust traps for different elements. Volatile and refractory elements are depleted from TW Hya's hot gas by factors of ~10^2^ and up to 10^5^, respectively. The abundances of the trapped solids are consistent with a combination of primitive Solar System bodies. Dust traps beyond the CO and N_2_ snow line cumulatively sequester 96% of the total dust flux, while the trap at 2AU, near the H_2_O snow line, retains 3%. The high depletions of Si, Mg, and Ca are explained by a third trap at 0.3AU with >95% dust retention. TW Hya sports a significant volatile reservoir rich in C- and N-ices in its outer submillimeter ring structure. However, unless the inner disk was enhanced in C by earlier radial transport, typical C destruction mechanisms and the lack of a C resupply should leave the terrestrial planet-forming region of TW Hya "dry" and carbon-poor. Any planets that form within the silicate dust trap at 0.3 AU could resemble Earth in terms of the degree of their volatile depletion.
- ID:
- ivo://CDS.VizieR/J/A+AS/106/165
- Title:
- Near-IR imaging photometry of NGC 1333
- Short Name:
- J/A+AS/106/165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-IR (NIR) J, H and K mosaic images of the active star forming region associated with the optical reflection nebula NGC 1333. These observations cover an area of 10'x10' and are centered on the energetic outflow source SSV 13. From these data, we have obtained NIR photometry of 134 objects down to a 5{sigma} limiting K magnitude of mK=16.2 and a conservative survey completeness limit of mK=16.0. With the addition of new optical R and I band CCD photometry, and both (sub)mm line and continuum maps, we analyse and discuss the region's morphology and spatial source distribution with additional reference to existing multi-wavelength data.
- ID:
- ivo://CDS.VizieR/J/A+A/376/982
- Title:
- Near-IR observations of young binaries
- Short Name:
- J/A+A/376/982
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using near-infrared speckle interferometry we have obtained resolved JHK-photometry for the components of 58 young binary systems.
- ID:
- ivo://CDS.VizieR/J/A+A/452/245
- Title:
- Near-IR photometry of PMS stars in rho Oph
- Short Name:
- J/A+A/452/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to provide a measurement of the mass accretion rate in a large, complete sample of objects in the core of the star forming region rho Oph. The sample includes most of the objects (104 out of 111) with evidence of a circumstellar disk from mid-infrared photometry; it covers a stellar mass range from about 0.03 to 3M_{sun}_ and it is complete to a limiting mass of ~0.05M_{sun}_. We used J and K-band spectra to derive the mass accretion rate of each object from the intensity of the hydrogen recombination lines, Pa{beta} or Br{gamma}. For comparison, we also obtained similar spectra of 35 diskless objects.
