- ID:
- ivo://CDS.VizieR/J/A+A/575/A120
- Title:
- DANCe study of M35 (NGC 2168)
- Short Name:
- J/A+A/575/A120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Messier 35 (NGC 2168) is an important young nearby cluster. Its age, richness and relative proximity make it a privileged target for stellar evolution studies. The Kepler K2 mission recently observed it and provided high accuracy photometric time series of a large number of sources in this area of the sky. Identifying the cluster's members is therefore of high importance to optimize the interpretation and analysis of the Kepler K2 data. We aim at identifying the cluster's members by deriving membership probabilities for the sources within 1 degree of the cluster's center, going further away than equivalent previous studies. We measure accurate proper motions and multi-wavelength (optical and near-infrared) photometry using ground based archival images of the cluster. We use these measurements to compute membership probabilities. The list of candidate members from Barrado y Navascues et al. (2001ApJ...546.1006B, Cat. J/ApJ/546/1006) is used as training set to identify the cluster's locus in a multi-dimensional space made of proper motions, luminosities and colors. The final catalog includes 338892 sources with multi-wavelength photometry. Approximately half (194452) were detected at more than two epochs and we measured their proper motion and used it to derive membership probability. A total of 4349 candidate members with membership probabilities greater than 50% are found in this sample in the luminosity range between 10 and 22mag. The slow proper motion of the cluster and the overlap of its sequence with the field and background sequences in almost all color-magnitude and color-color diagrams complicate the analysis and the contamination level is expected to be significant. Our study nevertheless provides a coherent and quantitative membership analysis of Messier 35 based on a large fraction of the best ground-based data sets obtained over the past 18 years. As such, it represents a valuable input for follow-up studies using in particular the Kepler K2 photometric time series.
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- ID:
- ivo://CDS.VizieR/J/ApJ/850/83
- Title:
- DANCING-ALMA. I. submm/mm continuum sources
- Short Name:
- J/ApJ/850/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the large statistics of the galaxy effective radius Re in the rest-frame far-infrared (FIR) wavelength R_e(FIR)_ obtained from 1627 Atacama Large Millimeter/submillimeter Array (ALMA) 1mm band maps that become public by 2017 July. Our ALMA sample consists of 1034 sources with the star formation rate ~100-1000M_{sun}_/yr and the stellar mass ~10^10^-10^11.5^M_{sun}_ at z=0-6. We homogeneously derive R_e(FIR)_ and FIR luminosity LFIR of our ALMA sources via the uv-visibility method with the exponential disk model, carefully evaluating selection and measurement incompletenesses by realistic Monte-Carlo simulations. We find that there is a positive correlation between R_e(FIR)_ and LFIR at the >99% significance level. The best-fit power-law function, R_e(FIR)_{propto}L_FIR_^{alpha}^, provides {alpha}=0.28+/-0.07, and shows that R_e(FIR)_ at a fixed LFIR decreases toward high redshifts. The best-fit {alpha} and the redshift evolution of R_e(FIR)_ are similar to those of Re in the rest-frame UV (optical) wavelength R_e(UV)_ (R_e(Opt)_) revealed by Hubble Space Telescope (HST) studies. We identify that our ALMA sources have significant trends of R_e(FIR)_<~R_e(UV)_ and R_e(Opt)_, which suggests that the dusty starbursts take place in compact regions. Moreover, R_e(FIR)_ of our ALMA sources is comparable to R_e(Opt)_ of quiescent galaxies at z~1-3 as a function of stellar mass, supporting the evolutionary connection between these two galaxy populations. We also investigate rest- frame UV and optical morphologies of our ALMA sources with deep HST images, and find that ~30%-40% of our ALMA sources are classified as major mergers. This indicates that dusty starbursts are triggered by not only the major mergers but also the other mechanism(s).
- ID:
- ivo://CDS.VizieR/J/A+A/545/A54
- Title:
- Danks 1, Danks 2, and RCW 79 variables
- Short Name:
- J/A+A/545/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ESO Public Survey "VISTA Variables in the Via Lactea"' (VVV) provides deep multi-epoch infrared observations for unprecedented 562 sq. degrees of the Galactic bulge, and adjacent regions of the disk. The VVV observations will foster the construction of a sample of Galactic star clusters with reliable and homogeneously derived physical parameters (e.g., age, distance, and mass, etc.). In this first paper in a series, the methodology employed to establish cluster parameters for the envisioned database are elaborated upon by analysing four known young open clusters: Danks1, Danks2, RCW79, and DBS132. The analysis offers a first glimpse of the information that can be gleaned from the VVV observations for clusters in the final database. Wide-field, deep JHK_s_ VVV observations, combined with new infrared spectroscopy, are employed to constrain fundamental parameters for a subset of clusters. Results are inferred from VVV near-infrared photometry and numerous low resolution spectra (typically more than 10 per cluster). The high quality of the spectra and the deep wide-field VVV photometry enables us to precisely and independently determine the characteristics of the clusters studied, which we compare to previous determinations. An anomalous reddening law in the direction of the Danks clusters is found, specifically E(J-H)/E(H-Ks)=2.20+/-0.06, which exceeds published values for the inner Galaxy. The G305 star forming complex, which includes the Danks clusters, lies beyond the Sagittarius-Carina spiral arm and occupies the Centaurus arm. Finally, the first deep infrared colour-magnitude diagram of RCW79 is presented, which reveals a sizeable pre-main sequence population. A list of candidate variable stars in G305 region is reported. This study demonstrates the strength of the dataset and methodology employed, and constitutes the first step of a broader study which shall include reliable parameters for a sizeable number of poorly characterised and/or newly discovered clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/417/1210
- Title:
- DA-white dwarfs from SDSS and UKIDSS
- Short Name:
- J/MNRAS/417/1210
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a method which uses colour-colour cuts on the Sloan Digital Sky Survey (SDSS) photometry to select white dwarfs with hydrogen-rich (DA) atmospheres without the recourse to spectroscopy. This method results in a sample of DA white dwarfs that is 95 per cent complete at an efficiency of returning a true DA white dwarf of 62 per cent. The approach was applied to SDSS Data Release 7 for objects with and without SDSS spectroscopy.
- ID:
- ivo://CDS.VizieR/J/ApJ/760/26
- Title:
- DA white dwarfs infrared photometry
- Short Name:
- J/ApJ/760/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near- and mid-infrared photometry and spectroscopy from PAIRITEL, IRTF, and Spitzer of a metallicity-unbiased sample of 117 cool, hydrogen-atmosphere white dwarfs (WDs) from the Palomar-Green survey and find five with excess radiation in the infrared, translating to a 4.3^+2.7^_-1.2_% frequency of debris disks. This is slightly higher than, but consistent with the results of previous surveys. Using an initial-final mass relation, we apply this result to the progenitor stars of our sample and conclude that 1-7M_{sun}_ stars have at least a 4.3% chance of hosting planets; an indirect probe of the intermediate-mass regime eluding conventional exoplanetary detection methods. Alternatively, we interpret this result as a limit on accretion timescales as a fraction of WD cooling ages; WDs accrete debris from several generations of disks for ~10Myr. The average total mass accreted by these stars ranges from that of 200km asteroids to Ceres-sized objects, indicating that WDs accrete moons and dwarf planets as well as solar system asteroid analogs.
- ID:
- ivo://CDS.VizieR/J/A+A/463/1029
- Title:
- DCld303-14.8 & Thumbprint Nebula JHKs phot.
- Short Name:
- J/A+A/463/1029
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of radial density structure of the star forming globule, DCld303.8-14.2 (DC303), and a non-star forming globule, Thumbprint Nebula (TPN), using near-infrared data taken with the ISAAC instrument on the Very Large Telescope. We derive the extinction through the globules using the color excess technique and examine the radial density distribution using Bonnor-Ebert and power-law models.
- ID:
- ivo://CDS.VizieR/J/A+A/593/A51
- Title:
- Debris discs around nearby FGK stars
- Short Name:
- J/A+A/593/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Debris discs are a consequence of the planet formation process and constitute the fingerprints of planetesimal systems. Their counterparts in the solar system are the asteroid and Edgeworth-Kuiper belts. The aim of this paper is to provide robust numbers for the incidence of debris discs around FGK stars in the solar neighbourhood. The full sample of 177 FGK stars with d>=20pc proposed for the DUst around NEarby Stars (DUNES) survey is presented. Herschel/PACS observations at 100 and 160{mu}m were obtained, and were complemented in some cases with data at 70{mu}m and at 250, 350, and 500{mu}m SPIRE photometry. The 123 objects observed by the DUNES collaboration were presented in a previous paper. The remaining 54 stars, shared with the Disc Emission via a Bias-free Reconnaissance in IR and Sub-mm (DEBRIS) consortium and observed by them, and the combined full sample are studied in this paper. The incidence of debris discs per spectral type is analysed and put into context together with other parameters of the sample, like metallicity, rotation and activity, and age. The subsample of 105 stars with d>=15pc containing 23 F, 33 G, and 49 K stars is complete for F stars, almost complete for G stars, and contains a substantial number of K stars from which we draw solid conclusions on objects of this spectral type. The incidence rates of debris discs per spectral type are 0.26^+0.21^_-0.14_ (6 objects with excesses out of 23 F stars), 0.21^+0.17^_-0.11_ (7 out of 33 G stars), and 0.20^0.14^_-0.09_ (10 out of 49 K stars); the fraction for all three spectral types together is 0.22^+0.08^_-0.07_ (23 out of 105 stars). The uncertainties correspond to a 95% confidence level. The medians of the upper limits of L_dust_/L* for each spectral type are 7.8x10^-7^ (F), 1.4x10^-6^ (G), and 2.2x10^-6^ (K); the lowest values are around 4.0x10^-7^. The incidence of debris discs is similar for active (young) and inactive (old) stars. The fractional luminosity tends to drop with increasing age, as expected from collisional erosion of the debris belts.
- ID:
- ivo://CDS.VizieR/J/AJ/148/3
- Title:
- Debris disk candidates detected with AKARI/FIS
- Short Name:
- J/AJ/148/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We cross-correlate the Hipparcos main-sequence star catalog with the AKARI/FIS catalog and identify 136 stars (at >90% reliability) with far-infrared detections in at least one band. After rejecting 57 stars classified as young stellar objects, Be stars and other type stars with known dust disks or with potential contaminations, and 4 stars without infrared excess emission, we obtain a sample of 75 candidate stars with debris disks. Stars in our sample cover spectral types from B to K with most being early types. This represents a unique sample of luminous debris disks that derived uniformly from an all-sky survey with a spatial resolution factor of four better than the previous such survey by IRAS. Moreover, by collecting the infrared photometric data from other public archives, almost three-quarters of them have infrared excesses in more than one band, allowing an estimate of the dust temperatures. We fit the blackbody model to the broadband spectral energy distribution of these stars to derive the statistical distribution of the disk parameters. Four B stars with excesses in four or more bands require a double blackbody model, with the high one around 100 or 200K and the low one around 40-50K.
- ID:
- ivo://CDS.VizieR/J/ApJ/688/597
- Title:
- Debris disks in NGC 2232
- Short Name:
- J/ApJ/688/597
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe Spitzer IRAC and MIPS observations of the nearby 25Myr old open cluster NGC 2232. Combining these data with ROSAT All-Sky Survey observations, proper motions, and optical photometry/spectroscopy, we construct a list of highly probable cluster members. We identify one A-type star, HD 45435, that has definite excess emission at 4.5-24um indicative of debris from terrestrial planet formation. We also identify 2-4 late-type stars with possible 8um excesses and 8 early-type stars with definite 24um excesses. Constraints on the dust luminosity and temperature suggest that the detected excesses are produced by debris disks. From our sample of B and A stars, stellar rotation appears to be correlated with 24um excess, a result that would be expected if massive primordial disks evolve into massive debris disks. To explore the evolution of the frequency and magnitude of debris around A-type stars, we combine our results with data for other young clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/705/1646
- Title:
- Debris disks in Upper Sco
- Short Name:
- J/ApJ/705/1646
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present MIPS 24um and 70um photometry for 205 members of the Upper Scorpius OB Association. These data are combined with published MIPS photometry for 15 additional association members to assess the frequency of circumstellar disks around 5Myr old stars with spectral types between B0 and M5. Twelve stars have a detectable 70um excess, each of which also has a detectable 24um excess. A total of 54 stars are identified with a 24um excess more than 32% above the stellar photosphere. The MIPS observations reveal 19 excess sources - 8 A/F/G stars and 11 K/M stars - that were not previously identified with an 8um or 16um excess. The lack of short-wavelength emission and the weak 24um excess suggests that these sources are debris systems or the remnants of optically thick primordial disks with inner holes. Despite the wide range of luminosities of the stars hosting apparent debris systems, the excess characteristics are consistent with all stars having dust at similar orbital radii after factoring in variations in the radiation blowout particle size with spectral type. The results for Upper Sco are compared to similar photometric surveys from the literature to re-evaluate the evolution of debris emission.
