Search Publications
Observations of [OI]63 µm line emission in main-sequence galaxies at z 1.5
Daddi, E.; Valtchanov, I.; Walter, F. +9 more
We present Herschel-PACS spectroscopy of four main-sequence star-forming galaxies at z ~ 1.5. We detect [OI]63 µm line emission in BzK-21000 at z = 1.5213, and measure a line luminosity, $L_{\rm [O\, {\small I}]63\, \mu m} = (3.9\pm 0.7)\times 10^9$ L⊙. Our PDR modelling of the interstellar medium in BzK-21000 suggests a UV radiat…
Nearby Quintuple Systems κ Tucanae and ξ Scorpii
Tokovinin, Andrei
Architecture and parameters of two wide, nearby hierarchical systems containing five solar-type stars each, κ Tuc and ξ Sco, are studied. Using Gaia astrometry and photometry, masses are determined from visual orbits and isochrones, and effective temperatures from spectra or colors. Both systems are ∼2 Gyr old. Their spatial motion corresponds to …
VVV-WIT-01: highly obscured classical nova or protostellar collision?
Minniti, D.; Masetti, N.; Krause, M. +18 more
A search of the first Data Release of the VISTA Variables in the Via Lactea (VVV) Survey discovered the exceptionally red transient VVV-WIT-01 (H - Ks = 5.2). It peaked before March 2010, then faded by ∼9.5 mag over the following 2 yr. The 1.6-22 µm spectral energy distribution in March 2010 was well fit by a highly obscured black…
Models of bars - II. Exponential profiles
Evans, N. W.; Sanders, J. L.; McGough, D. P.
We present a new model for galactic bars with exponentially falling major axis luminosity profiles and Gaussian cross-sections. This is based on the linear superposition of Gaussian potential-density pairs with an exponential weight function, using an extension of the method originally introduced by Long & Murali. We compute the density, poten…
Circumstellar CO J = 3→2 detected around the evolving metal-poor ([Fe/H] ≈ -1.15 dex) AGB star RU Vulpeculae
Zijlstra, A. A.; Richards, A. M. S.; McDonald, I. +2 more
We report the first detection of CO J = 3→2 around a truly metal-poor evolved star. RU Vulpeculae is modelled to have Teff ≈ 3620 K, L ≈ 3128 ± 516 L⊙, log(g) = 0.0 ± 0.2 dex and [Fe/H] = -1.3 to -1.0 dex, and is modelled to have recently undergone a thermal pulse. Its infrared flux has approximately doubled over 35 yr. ALMA …
Exploring the nature and synchronicity of early cluster formation in the Large Magellanic Cloud - V. Multiple populations in ancient globular clusters
Ventura, Paolo; Cohen, Roger E.; Sarajedini, Ata +10 more
We examine four ancient Large Magellanic Cloud (LMC) globular clusters (GCs) for evidence of multiple stellar populations using the Advanced Camera for Surveys and Wide Field Camera 3 on the Hubble Space Telescope Programme GO-14164. NGC 1466, NGC 1841, and NGC 2257 all show evidence for a redder, secondary population along the main sequence. Reti…
Abundances from integrated spectra of 47 Tucanae (NGC 104)
Trevisan, M.; Barbuy, B.; Rennó, C. +1 more
47 Tucanae is among the most studied and observed globular clusters, given its proximity. The aim of this work is to study in detail the integrated spectrum of 47 Tucanae, as a template, in order to have a list of reliable lines that are validated for a moderate spectral resolution case. The spectrum of 47 Tucanae is reproduced by computing synthe…
The nature of the NGC 2546: Not one but two open clusters
González, J. F.; Veramendi, M. E.; Alejo, A. D.
Context. As part of a broader project on the role of binary stars in clusters, we present a spectroscopic study of the open cluster NGC 2546, which is a large cluster lacking previous spectroscopic analysis.
Aims: We report the finding of two open clusters in the region of NGC 2546. For the two star groups, we determine radial velocity, paral…
Identifying Exo-Earth Candidates in Direct Imaging Data through Bayesian Classification
Apai, Dániel; Bixel, Alex
Future space telescopes may be able to directly image between approximately 10 and 100 planets with sizes and orbits consistent with habitable surface conditions (“exo-Earth candidates” or EECs), but observers will face difficulty in distinguishing these from the potentially hundreds of nonhabitable “false positives” which will also be detected. T…
The Statistics of Extended Debris Disks Measured with Gaia and Planck
Jain, Bhuvnesh; Nibauer, Jacob; Baxter, Eric
Thermal emission from debris disks around stars has been measured using targeted and resolved observations. We present an alternative likelihood-based approach in which temperature maps from the Planck cosmic microwave background (CMB) survey at 857 and 545 GHz are analyzed in conjunction with stellar positions from Gaia to estimate the fraction o…