- ID:
- ivo://CDS.VizieR/J/MNRAS/426/3403
- Title:
- UKIDSS-GCS {alpha} Per members
- Short Name:
- J/MNRAS/426/3403
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a deep (J=19.1mag) infrared (ZY JHK) survey over the full {alpha} Per open cluster extracted from the Data Release 9 of the United Kingdom Infrared Telescope Infrared Deep Sky Survey Galactic Clusters Survey (UKIDSS). We have selected ~700 cluster member candidates in ~56 square degrees in {alpha} Per by combining photometry in five near-infrared passbands and proper motions derived from the multiple epochs provided by the UKIDSS Galactic Clusters Survey (GCS) Data Release 9 (DR9). We also provide revised membership for all previously published {alpha} Per low-mass stars and brown dwarfs recovered in GCS based on the new photometry and astrometry provided by DR9.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/3419
- Title:
- UKIDSS GCS Praesepe members
- Short Name:
- J/MNRAS/426/3419
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Over the past decades open clusters have been the subject of many studies. Such studies are crucial considering that the universality of the initial mass function is still a subject of current investigations. Praesepe is an interesting open cluster for the study of the stellar and substellar mass function (MF), considering its intermediate age and its nearby distance. Here we present the results of a wide-field, near-infrared study of Praesepe using the Data Release 9 of the United Kingdom Infrared Telescope Infrared Deep Sky Survey Galactic Clusters Survey. We obtained cluster candidates of Praesepe based on a 3{sigma} astrometric and five-band photometric selection.
- ID:
- ivo://CDS.VizieR/J/MNRAS/431/3222
- Title:
- UKIDSS GCS Upper Sco members
- Short Name:
- J/MNRAS/431/3222
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a proper motion wide-field near-infrared survey of the entire Upper Sco (USco) association (about 160 square degrees) released as part of the UKIRT Infrared Deep Sky (UKIDSS) Galactic Clusters Survey (GCS) Data Release 10 (DR10). We have identified a sample of about 400 astrometric and photometric member candidates combining proper motions and photometry in five near-infrared passbands and another 286 with HK photometry and 2MASS/GCS proper motions. We also provide revised membership for all previously published USco low-mass stars and substellar members based on our selection and identify new candidates, including in regions affected by extinction. We find negligible variability between the two K-band epochs, below the 0.06mag rms level. We estimate an upper limit of 2.2% for wide common proper motions with projected physical separations less than 15000AU. We derive a disk frequency for USco low-mass stars and brown dwarfs between 26 and 37%, in agreement with estimates in IC 348 and sigma Ori. We derive the mass function of the association and find it consistent with the (system) mass function of the solar neighbourhood and other clusters surveyed by the GCS in the 0.2-0.03M_{sun}_ mass range. We confirm the possible excess of brown dwarfs in USco.
- ID:
- ivo://CDS.VizieR/J/MNRAS/503/270
- Title:
- UKIDSS JHK photometry of W33A
- Short Name:
- J/MNRAS/503/270
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- W33A is a well-known example of a high-mass young stellar object showing evidence of a circumstellar disc. We revisited the -band NIFS/Gemini North observations of the W33A protostar using principal components analysis tomography and additional post-processing routines. Our results indicate the presence of a compact rotating disc based on the kinematics of the CO absorption features. The position-velocity diagram shows that the disc exhibits a rotation curve with velocities that rapidly decrease for radii larger than 0.1" (~250AU) from the central source, suggesting a structure about four times more compact than previously reported.We derived a dynamical mass of 10.0^+4.1^_-2.2_M_{sun}_ for the "disc+protostar" system, about ~33% smaller than previously reported, but still compatible with high-mass protostar status. A relatively compact H_2_ wind was identified at the base of the large-scale outflow of W33A, with a mean visual extinction of ~63mag. By taking advantage of supplementary near-infrared maps, we identified at least two other point-like objects driving extended structures in the vicinity of W33A, suggesting that multiple active protostars are located within the cloud. The closest object (SourceB) was also identified in the NIFS field of view as a faint pointlike object at a projected distance of ~7000AU from W33A, powering extended K-band continuum emission detected in the same field. Another source (SourceC) is driving a bipolar H_2_ jet aligned perpendicular to the rotation axis of W33A.
- ID:
- ivo://CDS.VizieR/J/ApJ/892/91
- Title:
- UKIRT NIR and Spitzer MIR phot. in NGC 6822
- Short Name:
- J/ApJ/892/91
- Date:
- 19 Jan 2022 08:59:33
- Publisher:
- CDS
- Description:
- The nearby (~500kpc) metal-poor ([Fe/H]~-1.2; Z~30%Z_{sun}_) star-forming galaxy NGC 6822 has a metallicity similar to systems at the epoch of peak star formation. Through identification and study of dusty and dust-producing stars, it is therefore a useful laboratory to shed light on the dust life cycle in the early universe. We present a catalog of sources combining near- and mid-IR photometry from the United Kingdom Infrared Telescope (J, H, and K) and the Spitzer Space Telescope (IRAC 3.6, 4.5, 5.8, and 8.0{mu}m and MIPS 24{mu}m). This catalog is employed to identify dusty and evolved stars in NGC 6822 utilizing three color-magnitude diagrams (CMDs). With diagnostic CMDs covering a wavelength range spanning the near- and mid-IR, we develop color cuts using kernel density estimate (KDE) techniques to identify dust-producing evolved stars, including red supergiant (RSG) and thermally pulsing asymptotic giant branch (TP-AGB) star candidates. In total, we report 1292 RSG candidates, 1050 oxygen-rich AGB star candidates, and 560 carbon-rich AGB star candidates with high confidence in NGC 6822. Our analysis of the AGB stars suggests a robust population inhabiting the central stellar bar of the galaxy, with a measured global stellar metallicity of [Fe/H]=-1.286+/-0.095, consistent with previous studies. In addition, we identify 277 young stellar object (YSO) candidates. The detection of a large number of YSO candidates within a centrally located, compact cluster reveals the existence of an embedded, high-mass star formation region that has eluded previous detailed study. Spitzer I appears to be younger and more active than the other prominent star-forming regions in the galaxy.
- ID:
- ivo://CDS.VizieR/J/ApJ/889/44
- Title:
- UKIRT obs. of red supergiants in M31
- Short Name:
- J/ApJ/889/44
- Date:
- 17 Jan 2022 11:49:04
- Publisher:
- CDS
- Description:
- The mass-loss rates of red supergiant stars (RSGs) are poorly constrained by direct measurements, and yet the subsequent evolution of these stars depends critically on how much mass is lost during the RSG phase. In 2012 the Geneva evolutionary group updated their mass-loss prescription for RSGs with the result that a 20M_{sun}_ star now loses 10 times more mass during the RSG phase than in the older models. Thus, higher-mass RSGs evolve back through a second yellow supergiant phase rather than exploding as Type II-P supernovae, in accord with recent observations (the so-called "RSG Problem"). Still, even much larger mass-loss rates during the RSG phase cannot be ruled out by direct measurements of their current dust-production rates, as such mass loss is episodic. Here, we test the models by deriving a luminosity function for RSGs in the nearby spiral galaxy, M31, which is sensitive to the total mass loss during the RSG phase. We carefully separate RSGs from asymptotic giant branch stars in the color-magnitude diagram following the recent method exploited by Yang+ (2019, J/A+A/629/A91) in their Small Magellanic Cloud studies. Comparing our resulting luminosity function with that predicted by the evolutionary models shows that the new prescription for RSG mass loss does an excellent job of matching the observations, and we can readily rule out significantly larger values.
- ID:
- ivo://CDS.VizieR/J/A+AS/145/399
- Title:
- UKS 2 open cluster BV photometry
- Short Name:
- J/A+AS/145/399
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Colour-magnitude diagrams are presented for the first time, of the faint southern star cluster UKS 2, which was for a long time reported as a globular cluster candidate. The V vs. B-V diagrams indicate that UKS 2 is an open cluster with age comparable to that of the Hyades. It has a reddening of E(B-V)=0.40 and is located at a distance from the Sun of d_{sun}_=~7kpc. The cluster is located outside the solar radius at galactocentric distance projected on the plane r_GC_=~11kpc, and a height z=~-370pc.
- ID:
- ivo://CDS.VizieR/J/ApJ/797/54
- Title:
- ULIRGs in the AKARI all-sky survey
- Short Name:
- J/ApJ/797/54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new catalog of 118 ultraluminous infrared galaxies (ULIRGs) and one hyperluminous infrared galaxy (HLIRG) by cross-matching the AKARI all-sky survey with the Sloan Digital Sky Survey Data Release 10 (SDSS DR10) and the final data release of the Two-Degree Field Galaxy Redshift Survey. Forty of the ULIRGs and one HLIRG are new identifications. We find that ULIRGs are interacting pair galaxies or ongoing or postmergers. This is consistent with the widely accepted view: ULIRGs are major mergers of disk galaxies. We confirm the previously known positive trend between the active galactic nucleus fraction and infrared luminosity. We show that ULIRGs have a large offset from the main sequence up to z ~ 1; their offset from the z ~ 2 "main sequence" is relatively smaller. We find a result consistent with the previous studies showing that, compared to local star-forming SDSS galaxies of similar mass, local ULIRGs have lower oxygen abundances. We demonstrate for the first time that ULIRGs follow the fundamental metallicity relation (FMR). The scatter of ULIRGs around the FMR (0.09 dex-0.5 dex) is comparable to the scatter of z ~ 2-3 galaxies. We provide the largest local (0.050 <z < 0.487) ULIRG catalog with stellar masses, star-formation rates, gas metallicities, and optical colors.
- ID:
- ivo://CDS.VizieR/J/A+A/598/A1
- Title:
- [U]LIRGs - on the trail of AGN's types
- Short Name:
- J/A+A/598/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this work is to characterize physical properties of Ultra Luminous Infrared Galaxies (ULIRGs) and Luminous Infrared Galaxies (LIRGs) detected in the far-infrared (FIR) 90um band in the AKARI Deep Field-South (ADF-S) survey. In particular, we want to estimate the active galactic nucleus (AGN) contribution to the LIRGs and ULIRGs' infrared emission and which types of AGNs are related to their activity. We examined 69 galaxies at redshift >=0.05 detected at 90um by the AKARI satellite in the AKARI Deep-Field South (ADF-S), with optical counterparts and spectral coverage from the ultraviolet to the FIR. We used two independent spectral energy distribution fitting codes: one fitting the SED from FIR to FUV (CIGALE) (we use the results from CIGALE as a reference) and gray-body + power spectrum fit for the infrared part of the spectra (CMCIRSED) in order to identify a subsample of ULIRGs and LIRGs, and to estimate their properties. A final catalog of 39 LIRGs and ULIRGs is used for our analysis.
- ID:
- ivo://CDS.VizieR/J/AJ/141/163
- Title:
- Ultimate light curve of SN 1998bw/GRB 980425
- Short Name:
- J/AJ/141/163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multicolor light curves of SN 1998bw which appeared in ESO184-G82 in close temporal and spatial association with GRB 980425. The light curves are based on observations conducted at Cerro Tololo Inter-American Observatory (CTIO) and data from the literature. The CTIO photometry reaches ~86-days after the gamma-ray burst (GRB) in U and ~160-days after the GRB in BV(RI)C. The observations in U extend the previously known coverage by about 30-days and determine the slope of the early exponential tail. We calibrate a large set of local standards in common with those of previous studies and use them to transform published observations of the supernova (SN) to our realization of the standard photometric system.
