- ID:
- ivo://CDS.VizieR/J/ApJ/749/79
- Title:
- Transition disks. II. Southern MoC
- Short Name:
- J/ApJ/749/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transition disk objects are pre-main-sequence stars with little or no near-IR excess and significant far-IR excess, implying inner opacity holes in their disks. Here we present a multifrequency study of transition disk candidates located in Lupus I, III, IV, V, VI, Corona Australis, and Scorpius. Complementing the information provided by Spitzer with adaptive optics (AO) imaging (NaCo, VLT), submillimeter photometry (APEX), and echelle spectroscopy (Magellan, Du Pont Telescopes), we estimate the multiplicity, disk mass, and accretion rate for each object in our sample in order to identify the mechanism potentially responsible for its inner hole. We find that our transition disks show a rich diversity in their spectral energy distribution morphology, have disk masses ranging from <~1 to 10M_JUP_, and accretion rates ranging from <~10^-11^ to 10^-7.7^M_{sun}_/yr. Of the 17 bona fide transition disks in our sample, three, nine, three, and two objects are consistent with giant planet formation, grain growth, photoevaporation, and debris disks, respectively. Two disks could be circumbinary, which offers tidal truncation as an alternative origin of the inner hole.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/592/A126
- Title:
- Transition disk survey
- Short Name:
- J/A+A/592/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Understanding disk evolution and dissipation is essential for studies of planet formation. Transition disks, i.e., disks with large dust cavities and gaps, are promising candidates of active evolution. About two dozen candidates, selected by their Spectral Energy Distribution (SED), have been confirmed to have dust cavities through millimeter interferometric imaging, but this sample is biased toward the brightest disks. The Spitzer surveys of nearby low-mass star-forming regions have resulted in more than 4000 young stellar objects (YSOs). Using color criteria, we selected a sample of ~150 candidates and an additional 40 candidates and known transition disks from the literature. The Spitzer data were complemented by new observations at longer wavelengths, including new JCMT and APEX submillimeter photometry, and WISE and Herschel-PACS mid- and far-infrared photometry. Furthermore, optical spectroscopy was obtained and stellar types were derived for 85% of the sample, including information from the literature. The SEDs were fit to a grid of RADMC-3D disk models with a limited number of parameters: disk mass, inner disk mass, scale height and flaring, and disk cavity radius, where the latter is the main parameter of interest. About 72% of our targets possibly have dust cavities based on the SED. The derived cavity sizes are consistent with imaging/modeling results in the literature, where available. Trends are found with the L_disk_ over L_*_ ratio and stellar mass and a possible connection with exoplanet orbital radii. A comparison with a previous study where color observables are used (Cieza et al., 2010, Cat. J/ApJ/712/925) reveals large overlap between their category of planet-forming disks and our transition disks with cavities. A large number of the new transition disk candidates are suitable for follow-up observations with ALMA.
- ID:
- ivo://CDS.VizieR/J/A+A/518/A25
- Title:
- Transits of HD40307b by Spitzer
- Short Name:
- J/A+A/518/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used Spitzer and its IRAC camera to search for the transit of the super-Earth HD 40307b. The hypothesis that the planet transits could not be firmly discarded from our first photometric monitoring of a transit window because of the uncertainty coming from the modeling of the photometric baseline. To obtain a firm result, two more transit windows were observed and a global Bayesian analysis of the three IRAC time series and the HARPS radial velocities was performed. Unfortunately, the hypothesis that the planet transited during the observed phase window is firmly rejected, while the probability that the planet does transit but that the eclipse was missed by our observations is nearly negligible (0.26%)
- ID:
- ivo://CDS.VizieR/J/MNRAS/396/964
- Title:
- T Tauri in and around bright-rimmed clouds
- Short Name:
- J/MNRAS/396/964
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to quantitatively testify the 'small-scale sequential star formation' hypothesis in and around bright-rimmed clouds (BRCs). As a continuation of the recent attempt by Ogura et al. (2007PASJ...59..199O), we have carried out BVIc photometry of four more BRC aggregates along with deeper re-observations of two previously observed BRCs. Again, quantitative age gradients are found in almost all the BRCs studied in the present work. Archival Spitzer/Infrared Array Camera data also support this result.
- ID:
- ivo://CDS.VizieR/J/A+A/525/A47
- Title:
- U-band photometry in sigma Orionis region
- Short Name:
- J/A+A/525/A47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the results of an U band survey with FORS1/VLT of a large area in the sigma Ori star-forming region. We combine the U-band photometry with literature data to compute accretion luminosity and mass accretion rates from the U-band excess emission for all objects (187) detected by Spitzer in the FORS1 field and classified by Hernandez et al. (2007, Cat. J/ApJ/662/1067) as likely members of the cluster.
- ID:
- ivo://CDS.VizieR/J/A+A/561/A49
- Title:
- 867um image of SBS 0335-052 with ALMA
- Short Name:
- J/A+A/561/A49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 Band 7 observations of an extremely metal-poor dwarf starburst galaxy in the Local Universe, SBS 0335-052 (12+log(O/H)~7.2). With these observations, dust is detected at 870um (ALMA Band 7), but 87% of the flux in this band is due to free-free emission from the starburst.
- ID:
- ivo://CDS.VizieR/J/A+A/538/A11
- Title:
- 70um-1.2mm and N_2_H+ maps of IRDC18454 (W43)
- Short Name:
- J/A+A/538/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The earliest stages of high-mass star formation are still poorly characterized. Densities, temperatures and kinematics are crucial parameters for simulations of high-mass star formation. It is also unknown whether the initial conditions vary with environment. We want to investigate the youngest massive gas clumps in the environment of extremely active star formation. We selected the IRDC18454 complex, directly associated with the W43 Galactic mini-starburst, and observed it in the continuum emission between 70um and 1.2mm with Herschel, APEX and the 30m telescope, and in spectral line emission of N_2_H+ and ^13^CO with the Nobeyama 45m, the IRAM 30m and the Plateau de Bure Interferometer.
- ID:
- ivo://CDS.VizieR/J/MNRAS/379/663
- Title:
- 850um observations of W3 giant molecular cloud
- Short Name:
- J/MNRAS/379/663
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have surveyed a ~0.9 square degree area of the W3 giant molecular cloud (GMC) and star-forming region in the 850-um continuum, using the Submillimetre Common-User Bolometer Array on the James Clerk Maxwell Telescope. A complete sample of 316 dense clumps were detected with a mass range from around 13 to 2500M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/ApJS/186/406
- Title:
- 350um polarimetry from CSO
- Short Name:
- J/ApJS/186/406
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a summary of data obtained with the 350um polarimeter, Hertz, at the Caltech Submillimeter Observatory. We give tabulated results and maps showing polarization vectors and intensity contours. The summary includes over 4300 individual measurements in 56 Galactic sources and two galaxies. Of these measurements, 2153 have P>=3{sigma}_p_ statistical significance. The median polarization of the entire data set is 1.46%.
- ID:
- ivo://CDS.VizieR/J/ApJS/249/1
- Title:
- 500um risers with HerMES & SPIRE drop-outs with S2CLS
- Short Name:
- J/ApJS/249/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of our systematic search for the reddest far-infrared (FIR) and submillimeter (sub-mm) galaxies using the data from the Herschel Multi-tiered Extragalactic Survey (HerMES) and the SCUBA2 Cosmological Legacy Survey (S2CLS). The red FIR galaxies are "500{mu}m risers," whose spectral energy distributions increase with wavelength across the three FIR passbands of the Spectral and Photometric Imaging REceiver (SPIRE) of Herschel. Within 106.5deg^2^ of the HerMES fields, we have selected 629 500{mu}m risers. The red sub-mm galaxies are "SPIRE drop-outs," which are prominent detections in the S2CLS 850{mu}m data but are extremely weak or invisible in the SPIRE bands. Within the 2.98deg^2^ common area of HerMES and S2CLS, we have selected 95 such objects. These very red sources could be dusty starbursts at high redshifts (z>~4-6) because the peak of their cold-dust emission heated by star formation is shifted to the reddest FIR/sub-mm bands. The surface density of 500{mu}m risers is ~8.2deg^-2^ at the >=20mJy level in 500{mu}m, while that of SPIRE drop-outs is ~19.3deg^-2^ at the >=5mJy level in 850{mu}m. Both types of objects could span a wide range of redshifts, however. Using deep radio data in these fields to further select the ones likely at the highest redshifts, we find that the surface density of z>6 candidates is 5.5deg^-2^ among 500{mu}m risers and is 0.8-13.6deg^-2^ among SPIRE drop-outs. If this is correct, the dust-embedded star formation processes in such objects could contribute comparably as Lyman-break galaxies to the global SFR density at z>6.
