- ID:
- ivo://CDS.VizieR/J/ApJ/759/49
- Title:
- Jovian Trojan asteroids with WISE/NEOWISE: taxonomy
- Short Name:
- J/ApJ/759/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present updated/new thermal model fits for 478 Jovian Trojan asteroids observed with the Wide-field Infrared Survey Explorer (WISE). Using the fact that the two shortest bands used by WISE, centered on 3.4 and 4.6{mu}m, are dominated by reflected light, we derive albedos of a significant fraction of these objects in these bands. While the visible albedos of both the C-, P-, and D-type asteroids are strikingly similar, the WISE data reveal that the albedo at 3.4{mu}m is different between C-/P- and D-types. The albedo at 3.4{mu}m can thus be used to classify the objects, with C-/P-types having values less than 10% and D-types have values larger than 10%. Classifying all objects larger than 50km shows that the D-type objects dominate both the leading cloud (L_4_), with a fraction of 84%, and trailing cloud (L_5_), with a fraction of 71%-80%. The two clouds thus have very similar taxonomic distribution for these large objects, but the leading cloud has a larger number of these large objects, L_4_/L_5_=1.34. The taxonomic distribution of the Jovian Trojans is found to be different from that of the large Hildas, which is dominated by C- and P-type objects. At smaller sizes, the fraction of D-type Hildas starts increasing, showing more similarities with the Jovian Trojans. If this similarity is confirmed through deeper surveys, it could hold important clues to the formation and evolution of the two populations. The Jovian Trojans does have similar taxonomic distribution to that of the Jovian irregular satellites, but lacks the ultra red surfaces found among the Saturnian irregular satellites and Centaur population.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/742/40
- Title:
- Jovian Trojans asteroids with WISE/NEOWISE
- Short Name:
- J/ApJ/742/40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the preliminary analysis of over 1739 known and 349 candidate Jovian Trojans observed by the NEOWISE component of the Wide-field Infrared Survey Explorer (WISE). With this survey the available diameters, albedos, and beaming parameters for the Jovian Trojans have been increased by more than an order of magnitude compared to previous surveys. We find that the Jovian Trojan population is very homogenous for sizes larger than ~10km (close to the detection limit of WISE for these objects). The observed sample consists almost exclusively of low albedo objects, having a mean albedo value of 0.07+/-0.03. The beaming parameter was also derived for a large fraction of the observed sample, and it is also very homogenous with an observed mean value of 0.88+/-0.13. Preliminary debiasing of the survey shows that our observed sample is consistent with the leading cloud containing more objects than the trailing cloud. We estimate the fraction to be N(leading)/N(trailing) ~1.4+/-0.2, lower than the 1.6+/-0.1 value derived by Szabo et al. (2007MNRAS.377.1393S).
- ID:
- ivo://CDS.VizieR/J/AJ/159/18
- Title:
- Jovian-type planets around M dwarfs with MIRI/JWST
- Short Name:
- J/AJ/159/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The upcoming launch of the James Webb Space Telescope (JWST) will dramatically increase our understanding of exoplanets, particularly through direct imaging. Microlensing and radial velocity surveys indicate that some M dwarfs host long-period giant planets. Some of these planets will likely be just a few parsecs away and a few astronomical units from their host stars, a parameter space that cannot be probed by existing high-contrast imagers. We studied whether the coronagraphs on the Mid-infrared Instrument on JWST can detect Jovian-type planets around nearby M dwarfs. For a sample of 27 very nearby M dwarfs, we simulated a sample of Saturn-Jupiter-mass planets with three atmospheric configurations and three orbital separations, observed in three different filters. We found that the f1550c 15.5 {mu}m filter is best suited for detecting Jupiter-like planets. Jupiter-like planets with patchy cloud cover, 2 au from their star, are detectable at 15.5 {mu}m around 14 stars in our sample, while Jupiters with clearer atmospheres are detectable around all stars in the sample. Saturns were most detectable at 10.65 and 11.4 {mu}m (f1065c and f1140c filters), but only with cloud-free atmospheres and within 3 pc (six stars). Surveying all 27 stars would take <170 hr of JWST integration time, or just a few hours for a shorter survey of the most favorable targets. There is one potentially detectable known planet in our sample: GJ 832 b. Observations aimed at detecting this planet should occur in 2024-2026, when the planet is maximally separated from the star.
- ID:
- ivo://CDS.VizieR/J/ApJ/522/113
- Title:
- 1Jy IRAS galaxies optical spectroscopy
- Short Name:
- J/ApJ/522/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper discusses the optical spectroscopic properties of the IRAS 1Jy sample (f_60_>1Jy) of ultraluminous infrared galaxies (ULIGs: L_IR_>10^12^L_{sun}; H_0_=75km/s/Mpc and q_0_=0). One hundred eight of the 118 1Jy ULIGs have been observed at {Delta}{lambda}=8.3{AA} resolution over the wavelength range ~4500-8900{AA}. These data are combined with large, previously published sets of optical spectroscopic data of lower luminosity infrared galaxies to look for systematic trends with infrared luminosity over the luminosity range L_IR_~10^10.5^-10^13^L_{sun}_.
- ID:
- ivo://CDS.VizieR/J/ApJ/768/128
- Title:
- K-band calibrated visibilities of 24 Be stars
- Short Name:
- J/ApJ/768/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on a high angular resolution survey of circumstellar disks around 24 northern sky Be stars. The K-band continuum survey was made using the CHARA Array long baseline interferometer (baselines of 30-331m). The interferometric visibilities were corrected for the flux contribution of stellar companions in those cases where the Be star is a member of a known binary or multiple system. For those targets with good (u, v) coverage, we used a four-parameter Gaussian elliptical disk model to fit the visibilities and to determine the axial ratio, position angle, K-band photospheric flux contribution, and angular diameter of the disk's major axis. For the other targets with relatively limited (u, v) coverage, we constrained the axial ratio, inclination angle, and/or disk position angle where necessary in order to resolve the degeneracy between possible model solutions. We also made fits of the ultraviolet and infrared spectral energy distributions (SEDs) to estimate the stellar angular diameter and infrared flux excess of each target. The mean ratio of the disk diameter (measured in K-band emission) to stellar diameter (from SED modeling) is 4.4 among the 14 cases where we reliably resolved the disk emission, a value which is generally lower than the disk size ratio measured in the higher opacity H{alpha} emission line. We estimated the equatorial rotational velocity from the projected rotational velocity and disk inclination for 12 stars, and most of these stars rotate close to or at the critical rotational velocity.
556. K-Band Galaxy Counts
- ID:
- ivo://CDS.VizieR/J/ApJS/96/117
- Title:
- K-Band Galaxy Counts
- Short Name:
- J/ApJS/96/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new counts of field galaxies from more than 20 arcmin^2 to a limiting magnitude of K = 20 and from 2 arcmin^2 to K = 21.5. At the faintest magnitudes, the counts are slightly higher than those reported previously, though still consistent given the small numbers of galaxies in the two samples.
- ID:
- ivo://CDS.VizieR/J/other/PASA/26.439
- Title:
- K-band images of star-forming regions
- Short Name:
- J/other/PASA/26.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep, wide-field, Ks-band (2.14-micron) images towards 87 southern massive star formation regions traced by methanol maser emission. Using point-spread function fitting, we generate 2.14-micron point source catalogues (PSCs) towards each of the regions. For the regions between 10{deg}<l<350{deg} and |b|<1, we match the 2.14-micron sources with the GLIMPSE point source catalogue to generate a combined 2.14- to 8.0-micron point source catalogue. We provide this data for the astronomical community to utilise in studies of the stellar content of embedded clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/360/587
- Title:
- K-band imaging of H{delta}-strong galaxies
- Short Name:
- J/MNRAS/360/587
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UFTI K-band imaging observations of 222 galaxies that are selected from the Sloan Digital Sky Survey to have unusually strong H{delta} absorption equivalent widths, W(H{delta})>4{AA}. Using GIM2D, the images are fitted with two-dimensional surface-brightness models consisting of a simple disc and bulge component to derive the fraction of luminosity in the bulge B/T.
- ID:
- ivo://CDS.VizieR/J/MNRAS/312/557
- Title:
- K-band Luminosity Function of Field Galaxies
- Short Name:
- J/MNRAS/312/557
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a measurement of the K-band luminosity function (LF) of field galaxies obtained from near-infrared imaging of a sample of 345 galaxies selected from the Stromlo-APM Redshift Survey. The LF is reasonably well fitted over the 10-mag range -26 < M(K-band) < -16 by a Schechter function with the parameters {alpha}=-1.16+/-0.19, M*=-23.58+/-0.42 and {phi*}=0.012+/-0.008 Mpc-3, assuming a Hubble constant of 100 km.s-1.Mpc-1. We have also estimated the LF for two subsets of galaxies subdivided by the equivalent width of the H{alpha} emission line at EW(H{alpha})=1nm. There is no significant difference in LF shape between the two samples, although there is a hint (~1{sigma} significance) that emission-line galaxies (ELGs) have M* roughly 1 mag fainter than non-ELGs. Contrary to the optical LF, there is no difference in the faint end slope {alpha} between the two samples.
- ID:
- ivo://CDS.VizieR/J/ApJ/540/1016
- Title:
- K-band & NICMOS photometry of Trapezium Cluster
- Short Name:
- J/ApJ/540/1016
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained images of the Trapezium Cluster (140"x140"; 0.3pc x 0.3pc) with the Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). Combining these data with new ground-based K-band spectra (R=800) and existing spectral types and photometry, we have constructed an H-R diagram and used it and other arguments to infer masses and ages.