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- ID:
- ivo://CDS.VizieR/J/MNRAS/344/887
- Title:
- Sub-mm observations of the HDF
- Short Name:
- J/MNRAS/344/887
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an extended analysis of the Submillimetre Common User Bolometer Array (SCUBA) observations of the Hubble Deep Field (HDF), expanding the areal coverage of the Hughes et al. (1998Natur.394..241H) study by a factor of ~1.8 and containing at least three further sources in addition to the five in that study. We also announce the public release of the reduced data products. The map is the deepest ever made in the submillimetre (submm), obtained in excellent conditions (median 850-{mu}m optical depth of 0.16).
- ID:
- ivo://CDS.VizieR/J/A+A/481/411
- Title:
- submm point sources from the Archeops experiment
- Short Name:
- J/A+A/481/411
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Archeops is a balloon-borne experiment, mainly designed to measure the Cosmic Microwave Background (CMB) temperature anisotropies at high angular resolution (~12 arcminutes). By-products of the mission are shallow sensitivity maps over a large fraction of the sky (about 30 %) in the millimetre and submillimetre range at 143, 217, 353 and 545GHz. From these maps, we produce a catalog of bright submillimetre point sources. We present in this paper the processing and analysis of the Archeops point sources. Redundancy across detectors is the key factor allowing us to distinguish glitches from genuine point sources in the 20 independent maps. We look at the properties of the most reliable point sources, totalling 304. Fluxes range from 1 to 10000Jy (at the frequencies covering 143 to 545GHz). All sources are either planets (2) or of galactic origin. The longitude range is from 75 to 198-degrees. Some of the sources are associated with the well-known Lynds Nebulae and HII compact regions in the galactic plane. A large fraction of the sources have an IRAS counterpart. Except for Jupiter, Saturn, the Crab and Cas A, all sources show a dust-emission-like modified blackbody emission spectrum. Temperatures cover a range from 7 to 27K. For the coldest sources (T<10K), a steep nu^beta^ emissivity law is found with a surprising beta~3 to 4. An inverse relationship between T and beta is observed. The number density of sources at 353GHz with flux brighter than 100Jy is of the order of 1 per degree of Galactic longitude. These sources will provide a strong check for the calibration of the Planck HFI focal plane geometry as a complement to planets. These very cold sources observed by Archeops should be prime targets for mapping observations by the Akari and Herschel space missions and ground-based observatories.
- ID:
- ivo://CDS.VizieR/J/ApJS/201/13
- Title:
- Submm polarization of Galactic clouds
- Short Name:
- J/ApJS/201/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hertz and SCUBA polarimeters, working at 350um and 850um, respectively, have measured the polarized emission in scores of Galactic clouds. Of the clouds in each data set, 17 were mapped by both instruments with good polarization signal-to-noise ratios. We present maps of each of these 17 clouds comparing the dual-wavelength polarization amplitudes and position angles at the same spatial locations.
- ID:
- ivo://CDS.VizieR/J/A+A/540/A51
- Title:
- Submm spectrum of deuterated glycolaldehydes
- Short Name:
- J/A+A/540/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Glycolaldehyde, a sugar-related interstellar prebiotic molecule, has recently been detected in two star-forming regions, Sgr B2(N) and G31.41+0.31. The detection of this new species increased the list of complex organic molecules detected in the interstellar medium (ISM) and adds another level to the chemical complexity present in space. Besides, this kind of organic molecule is important because it is directly linked to the origin of life. For many years, astronomers have been struggling to understand the origin of this high chemical complexity in the ISM. The study of deuteration may provide crucial hints.
- ID:
- ivo://CDS.VizieR/J/A+A/553/A84
- Title:
- (Sub)mm spectrum of deuterated methyl cyanides
- Short Name:
- J/A+A/553/A84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of deuterated abundant molecules is recognized as important in understanding molecular complexity in star-forming regions. We seek to assign the laboratory millimeter and submillimeter wave rotational spectra of the CHD_2_CN and CH_2_DCN deuterated isotopologues of methyl cyanide over a wide frequency range in order to provide precise spectral predictions for observations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/430/1171
- Title:
- Sub-stellar birth rate from UKIDSS
- Short Name:
- J/MNRAS/430/1171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new sample of mid-L to mid-T dwarfs with effective temperatures of 1100-1700K selected from the UKIDSS Large Area Survey (LAS) and confirmed with infrared spectra from X-shooter/Very Large Telescope. This effective temperature range is especially sensitive to the formation history of Galactic brown dwarfs and allows us to constrain the form of the sub-stellar birth rate, with sensitivity to differentiate between a flat (stellar like) birth rate and an exponentially declining form. We present the discovery of 63 new L and T dwarfs from the UKIDSS LAS DR7, including the identification of 12 likely unresolved binaries, which form the first complete sub-set from our programme, covering 495 square degrees of sky, complete to J=18.1. We compare our results for this sub-sample with simulations of differing birth rates for objects of masses 0.10-0.03M_{sun}_ and ages 1-10Gyr. We find that the more extreme birth rates (e.g. a halo type form) can likely be excluded as the true form of the birth rate. In addition, we find that although there is substantial scatter we find a preference for a mass function, with a power-law index {alpha} in the range -1<{alpha}<0 that is consistent (within the errors) with the studies of late T dwarfs.
- ID:
- ivo://CDS.VizieR/J/ApJ/799/155
- Title:
- Sub-stellar companions in Taurus
- Short Name:
- J/ApJ/799/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a large, high-spatial-resolution near-infrared imaging search for stellar and sub-stellar companions in the Taurus-Auriga star-forming region. The sample covers 64 stars with masses between those of the most massive Taurus members at ~3M_{sun}_ and low-mass stars at ~0.2M_{sun}_. We detected 74 companion candidates, 34 of these reported for the first time. Twenty-five companions are likely physically bound, partly confirmed by follow-up observations. Four candidate companions are likely unrelated field stars. Assuming physical association with their host star, estimated companion masses are as low as ~2M_Jup_. The inferred multiplicity frequency within our sensitivity limits between ~10-1500AU is 26.3_-4.9_^+6.6^%. Applying a completeness correction, 62%+/-14% of all Taurus stars between 0.7 and 1.4M_{sun}_ appear to be multiple. Higher order multiples were found in 1.8_-1.5_^+4.2^% of the cases, in agreement with previous observations of the field. We estimate a sub-stellar companion frequency of ~3.5%-8.8% within our sensitivity limits from the discovery of two likely bound and three other tentative very low-mass companions. This frequency appears to be in agreement with what is expected from the tail of the stellar companion mass ratio distribution, suggesting that stellar and brown dwarf companions share the same dominant formation mechanism. Further, we find evidence for possible evolution of binary parameters between two identified sub-populations in Taurus with ages of ~2Myr and ~20Myr, respectively.
- ID:
- ivo://CDS.VizieR/J/other/FrASS/8.624907
- Title:
- (Sub)Stellar companions of exoplanet hosts
- Short Name:
- J/other/FrASS/8.
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present the latest results of an ongoing multiplicity survey of exoplanet hosts, which was initiated at the Astrophysical Institute and University Observatory Jena, using data from the second data release of the ESA-Gaia mission. In this study the multiplicity of 289 targets was investigated, all located within a distance of about 500pc from the Sun. In total, 41 binary, and five hierarchical triple star systems with exoplanets were detected in the course of this project, yielding a multiplicity rate of the exoplanet hosts of about 16%. A total of 61 companions (47 stars, a white dwarf, and 13 brown dwarfs) were detected around the targets, whose equidistance and common proper motion with the exoplanet hosts were proven with their precise Gaia DR2 astrometry, which also agrees with the gravitational stability of most of these systems. The detected companions exhibit masses from about 0.016 up to 1.66M_{sun}_ and projected separations in the range between about 52 and 9555au.
- ID:
- ivo://CDS.VizieR/J/ApJ/610/1064
- Title:
- Substellar population of lambda Ori
- Short Name:
- J/ApJ/610/1064
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- By collecting optical and infrared photometry and low-resolution spectroscopy, we have identified a large number of low-mass stars and brown dwarf candidates belonging to the young cluster (~5Myr) associated with the binary star {lambda} Orionis. The lowest mass object found is an M8.5 with an estimated mass of 0.02M_{Sun}_ (~0.01M_{Sun}_ for objects without spectroscopic confirmation). For those objects with spectroscopy, the measured strength of the H{alpha} emission line follows a distribution similar to other clusters with the same age range, with larger equivalent widths for cooler spectral types.