- ID:
- ivo://CDS.VizieR/J/MNRAS/468/4006
- Title:
- Proto-cluster candidate fields
- Short Name:
- J/MNRAS/468/4006
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present SCUBA-2 follow-up of 61 candidate high-redshift Planck sources. Of these, 10 are confirmed strong gravitational lenses and comprise some of the brightest such submm sources on the observed sky, while 51 are candidate proto-cluster fields undergoing massive starburst events. With the accompanying Herschel-Spectral and Photometric Imaging Receiver observations and assuming an empirical dust temperature prior of 34^+13^_-9_K, we provide photometric redshift and far-IR luminosity estimates for 172 SCUBA-2-selected sources within these Planck overdensity fields. The redshift distribution of the sources peak between a redshift of 2 and 4, with one-third of the sources having S_500_/S_350_>1. For the majority of the sources, we find far-IR luminosities of approximately 10^13^L_{sun}_, corresponding to star formation rates of around 1000M_{sun}_/yr. For S_850_>8mJy sources, we show that there is up to an order of magnitude increase in star formation rate density and an increase in uncorrected number counts of 6 for S_850_>8mJy when compared to typical cosmological survey fields. The sources detected with SCUBA-2 account for only approximately 5 per cent of the Planck flux at 353 GHz, and thus many more fainter sources are expected in these fields.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/709/L114
- Title:
- Protoplanetary disks in PMS binaries
- Short Name:
- J/ApJ/709/L114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this Letter, I examine several observational trends regarding protoplanetary disks, debris disks, and exoplanets in binary systems in an attempt to constrain the physical mechanisms of planet formation in such a context. Binaries wider than about 100AU are indistinguishable from single stars in all aspects. Binaries in the 5-100AU range, on the other hand, are associated with shorter lived but (at least in some cases) equally massive disks. Furthermore, they form planetesimals and mature planetary systems at a similar rate as wider binaries and single stars, albeit with the peculiarity that they predominantly produce high-mass planets. I posit that the location of a stellar companion influences the relative importance of the core accretion and disk fragmentation planet formation processes, with the latter mechanism being predominant in binaries tighter than 100AU.
- ID:
- ivo://CDS.VizieR/J/ApJ/704/606
- Title:
- Protostars in the Vela Molecular Cloud
- Short Name:
- J/ApJ/704/606
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the infrared variability of young stellar objects by means of two Spitzer-IRAC images of the Vela Molecular Cloud D (VMR-D) obtained in observations separated in time by about six months. By using the same space-born IR instrumentation, this study eliminates all the unwanted effects due to differences in sensitivity, confusion, saturation, calibration, and filter bandpasses, issues that are usually unavoidable when comparing catalogs obtained from different instruments. The VMR-D map covers about 1.5deg^2^ of a site where star formation is actively ongoing. We are interested in accreting pre-main sequence variables whose luminosity variations are due to intermittent events of disk accretion (i.e., active T Tauri stars and EXor-type objects). The variable objects have been selected from a catalog of more than 170000 sources detected at an S/N>=5 (Cat. J/ApJ/719/9). We then searched the sample of variables for ones whose photometric properties such as IR excess, color-magnitude relationships, and spectral energy distribution, are as close as possible to those of known EXor's. Indeed, the latter are monitored in a more systematic way than T Tauri stars and the mechanisms that regulate the observed phenomenology are exactly the same. Hence, the modalities of the EXor behavior are adopted as driving criterion for selecting variables in general. We ultimately selected 19 bona fide candidates that constitute a well defined sample of new variable targets for further investigation (monitoring, spectroscopy). Out of these, 10 sources present a Spitzer MIPS 24um counterpart, and have been classified as three Class I, five flat spectrum, and two Class II objects, while the spectral energy distribution of the other nine sources is compatible with evolutionary phases older than Class I.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A118
- Title:
- Pr0211 RVs, photometry and activity indexes
- Short Name:
- J/A+A/588/A118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Open cluster (OC) stars share the same age and metallicity, and, in general, their age and mass can be estimated with higher precision than for field stars. For this reason, OCs are considered an important laboratory to study the relation between the physical properties of the planets and those of their host stars, and the evolution of planetary systems. However, only a handful of planets have been discovered around OC main-sequence stars so far, all of them in single-planet systems. For this reason we started an observational campaign within the GAPS collaboration to search for and characterize planets in OCs. We monitored the Praesepe member Pr 0211 to improve our knowledge of the eccentricity of the hot Jupiter (HJ) that is already known to orbit this star and search for additional intermediate-mass planets. An eccentric orbit for the HJ would support a planet-planet scattering process rather than a disk-driven migration after its formation. From 2012 to 2015, we collected 70 radial velocity (RV) measurements with HARPS-N and 36 with TRES of Pr 0211. Simultaneous photometric observations were carried out with the robotic STELLA telescope to characterize the stellar activity. We discovered a long-term trend in the RV residuals that we show as being due to the presence of a second, massive, outer planet. Orbital parameters for the two planets are derived by simultaneously fitting RVs and photometric light curves, with the activity signal modelled as a series of sinusoids at the rotational period of the star and its harmonics. We confirm that Pr 0211b has a nearly circular orbit (e=0.02+/-0.01), with an improvement of a factor two with respect to the previous determination of its eccentricity, and estimate that Pr 0211c has a mass Msini=7.9+/-0.2M_{jup}_, a period P>3500-days and a very eccentric orbit (e>0.60). This kind of peculiar system may be typical of open clusters if the planet-planet scattering phase, which lead to the formation of HJs, is caused by stellar encounters rather than by unstable primordial orbits. Pr 0211 is the first multi-planet system discovered around an OC star.
5335. PSCz catalog
- ID:
- ivo://CDS.VizieR/VII/221
- Title:
- PSCz catalog
- Short Name:
- VII/221
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The PSCz survey consists of redshifts, infra-red and optical photometry, and assorted other information for 18351 IRAS sources, mostly selected from the Point Source Catalog. The survey was designed to select almost all galaxies with flux brighter than 0.595Jy at 60 microns, over the 84% of the sky with extinction small enough that reliable and complete optical identification and spectroscopy was possible. Some of the sources are not galaxies and some are multiple entries for the same galaxy as described below. There are in total 15411 galaxies or possible galaxies, for which redshifts are available for 14677. The galaxies without redshift are mostly distant or at low latitude, as described below. Many of these galaxies have now been observed as part of the BTP project (Saunders et al 1999, astro-ph/9909174 "The Behind the Plane Survey"), and their redshifts will be included in future revisions of the catalogue. The main catalogue is "pscz.dat". There is also a short version of the catalogue, "psczvs.dat", containing sufficient information for most studies. They correspond to the version 2.2.
- ID:
- ivo://CDS.VizieR/J/A+A/593/L18
- Title:
- Pseudomagnitude distances applied to the Pleiades
- Short Name:
- J/A+A/593/L18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The concept of pseudomagnitude was recently introduced to estimate apparent stellar diameters using a strictly observational methodology. Pseudomagnitudes are distance indicators, which have the remarkable property of being reddening free. In this study, we use Hipparcos parallax measurements to compute the mean absolute pseudomagnitudes of solar neighbourhood dwarf stars as a function of their spectral type. To illustrate the use of absolute pseudomagnitudes, we derive the distance moduli of 360 Pleiades stars and find that the centroid of their distribution is 5.71+/-0.018, corresponding to a distance of 139.0+/-1.2pc. We locate the subset of ~50 Pleiades stars observed by Hipparcos at a mean distance of 135.5+/-3.7pc, thus confirming the frequently reported anomaly in the Hipparcos measurements of these stars.
5337. PSF models fits maps
- ID:
- ivo://CDS.VizieR/J/A+A/601/A86
- Title:
- PSF models fits maps
- Short Name:
- J/A+A/601/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Deep imaging of the diffuse light that is emitted by stellar fine structures and outer halos around galaxies is often now used to probe their past mass assembly. Because the extended halos survive longer than the relatively fragile tidal features, they trace more ancient mergers. We use images that reach surface brightness limits as low as 28.5-29mag/arcsec^2^ (g-band) to obtain light and color profiles up to 5-10 effective radii of a sample of nearby early-type galaxies. These were acquired with MegaCam as part of the CFHT MATLAS large programme. These profiles may be compared to those produced using simulations of galaxy formation and evolution, once corrected for instrumental effects. Indeed they can be heavily contaminated by the scattered light caused by internal reflections within the instrument. In particular, the nucleus of galaxies generates artificial flux in the outer halo, which has to be precisely subtracted. We present a deconvolution technique to remove the artificial halos that makes use of very large kernels. The technique, which is based on PyOperators, is more time efficient than the model-convolution methods that are also used for that purpose. This is especially the case for galaxies with complex structures that are hard to model. Having a good knowledge of the point spread function (PSF), including its outer wings, is critical for the method. A database of MegaCam PSF models corresponding to different seeing conditions and bands was generated directly from the deep images. We show that the difference in the PSFs in different bands causes artificial changes in the color profiles, in particular a reddening of the outskirts of galaxies having a bright nucleus. The method is validated with a set of simulated images and applied to three representative test cases: NGC 3599, NGC 3489, and NGC 4274, which exhibits a prominent ghost halo for two of them. This method successfully removes this.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A85
- Title:
- PSF photometric catalog of VVV survey data
- Short Name:
- J/A+A/632/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Vista Variables in the Via Lactea (VVV) survey has performed a multi-epoch near-infrared imaging of the inner Galactic plane. High-fidelity photometric catalogs are needed to utilize the data. We aim at producing a deep, point-spread-function (PSF) photometric catalog for the VVV survey J, H, and Ks band data. Specifically, we aim at taking advantage of all the epochs of the survey to reach high limiting magnitudes. We develop an automatic PSF-fitting pipeline based on the DaoPHOT algorithm and perform photometry on the stacked VVV images in J, H, and Ks bands. We present a PSF photometric catalog in the Vega system that contains about 926 million sources in the J, H, and Ks filters. About 10% of the sources are flagged as possible spurious detections. The 5 sigma limiting magnitudes of the sources with high reliability are about 20.8, 19.5, and 18.7mag in the J, H, and Ks band, respectively, depending on the local crowding condition. Our photometric catalog reaches on average about one magnitude deeper than the previously released PSF DoPHOT photometric catalog. It also includes less spurious detections. There are significant differences in the brightnesses of faint sources between our catalog and the previously released one. The likely origin of these differences is in the different photometric algorithms that are utilized; it is not straightforward to assess which catalog is more accurate in which situations. Our new catalog is beneficial especially for science goals that require high limiting magnitudes; our catalog reaches such in fields that have a relatively uniform source number density. Overall, the limiting magnitudes and completeness are different in the fields with different crowding conditions.
5339. psi Cen light curves
- ID:
- ivo://CDS.VizieR/J/A+A/456/651
- Title:
- psi Cen light curves
- Short Name:
- J/A+A/456/651
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an extensive high-precision light curve of the bright star psi Centauri, obtained with the star tracker on board the WIRE satellite, which shows that this star is an eclipsing binary. We have obtained photometry from the SMEI instrument on board the Coriolis satellite, which together with the WIRE data allows us to determine the orbital period and photometric parameters of the eclipsing system. The WIRE light curve contains 41334 datapoints with a point-to-point scatter of 2mmag and a total length of 28.7days. The SMEI light curve contains 3448 datapoints with a point-to- point scatter of 20mmag and spas several observing seasons.
- ID:
- ivo://CDS.VizieR/J/AJ/159/25
- Title:
- PS1 light curves and rotation periods of new asteroids
- Short Name:
- J/AJ/159/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The intranight trajectories of asteroids can be approximated by straight lines, and so are their intranight detections. Therefore, the Hough transform, a line detecting algorithm, can be used to connect the line-up detections to find asteroids. We applied this algorithm to a high-cadence Pan-STARRS 1 (PS1) observation, which was originally designed to collect asteroid light curves for rotation period measurements. The algorithm recovered most of the known asteroids in the observing fields and, moreover, discovered 3574 new asteroids with magnitude mainly of 21.5<w_p1_<22.5mag. This magnitude range is equivalent to subkilometer main-belt asteroids (MBAs), which usually lack rotation period measurements due to their faintness. Using the light curves of the 3574 new asteroids, we obtained 122 reliable rotation periods, of which 13 are super-fast rotators (SRFs; i.e., rotation period of <2hr). The required cohesion to survive these SFRs range from tens to thousands of Pa, a value consistent with the known SFRs and the regolith on the Moon and Mars. The higher chance of discovering SFRs here suggests that subkilometer MBAs probably harbor more SFRs.
