Search Publications
Dead or Alive? Long-term evolution of SN 2015bh (SNhunt275)
Brown, P. J.; Smartt, S. J.; Kotak, R. +37 more
Supernova (SN) 2015bh (or SNhunt275) was discovered in NGC 2770 on 2015 February with an absolute magnitude of Mr ∼ -13.4 mag, and was initially classified as an SN impostor. Here, we present the photometric and spectroscopic evolution of SN 2015bh from discovery to late phases (∼1 yr after). In addition, we inspect archival images of t…
HeCS-SZ: The Hectospec Survey of Sunyaev-Zeldovich-selected Clusters
Diaferio, Antonaldo; Hwang, Ho Seong; Geller, Margaret J. +1 more
We estimate cluster masses and velocity dispersions for 123 clusters from optical spectroscopy to compare the Sunyaev-Zeldovich (SZ) mass proxy and dynamical masses. Our new survey, HeCS-SZ (Hectospec Cluster Survey of SZ-selected clusters), includes 7721 new or remeasured redshifts from MMT/Hectospec observations of 21 SZ-selected clusters at red…
A self-consistent model for the evolution of the gas produced in the debris disc of β Pictoris
Pringle, J. E.; Kral, Q.; Juhász, A. +3 more
This paper presents a self-consistent model for the evolution of gas produced in the debris disc of β Pictoris. Our model proposes that atomic carbon and oxygen are created from the photodissociation of CO, which is itself released from volatile-rich bodies in the debris disc due to grain-grain collisions or photodesorption. While the CO lasts les…
High angular resolution Sunyaev-Zel'dovich observations of MACS J1423.8+2404 with NIKA: Multiwavelength analysis
Adam, R.; Arnaud, M.; Benoît, A. +42 more
The prototype of the NIKA2 camera, NIKA, is a dual-band instrument operating at the IRAM 30-m telescope, which can observe the sky simultaneously at 150 and 260 GHz. One of the main goals of NIKA (and NIKA2) is to measure the pressure distribution in galaxy clusters at high angular resolution using the thermal Sunyaev-Zel'dovich (tSZ) effect. Such…
The 31 Deg2 Release of the Stripe 82 X-Ray Survey: The Point Source Catalog
Schawinski, Kevin; Comastri, Andrea; Komossa, S. +23 more
We release the next installment of the Stripe 82 X-ray survey point-source catalog, which currently covers 31.3 deg2 of the Sloan Digital Sky Survey (SDSS) Stripe 82 Legacy field. In total, 6181 unique X-ray sources are significantly detected with XMM-Newton (>5σ) and Chandra (>4.5σ). This catalog release includes data from XMM-Ne…
The Diverse Origins of Neutron-capture Elements in the Metal-poor Star HD 94028: Possible Detection of Products of I-Process Nucleosynthesis
Roederer, Ian U.; Karakas, Amanda I.; Pignatari, Marco +1 more
We present a detailed analysis of the composition and nucleosynthetic origins of the heavy elements in the metal-poor ([Fe/H] = -1.62 ± 0.09) star HD 94028. Previous studies revealed that this star is mildly enhanced in elements produced by the slow neutron-capture process (s process; e.g., [Pb/Fe] = +0.79 ± 0.32) and rapid neutron-capture process…
Semi-empirical Modeling of the Photosphere, Chromosphere, Transition Region, and Corona of the M-dwarf Host Star GJ 832
France, Kevin; Fontenla, J. M.; Walkowicz, Lucianne M. +5 more
Stellar radiation from X-rays to the visible provides the energy that controls the photochemistry and mass loss from exoplanet atmospheres. The important extreme ultraviolet (EUV) region (10-91.2 nm) is inaccessible and should be computed from a reliable stellar model. It is essential to understand the formation regions and physical processes resp…
Evidence for Periodicity in 43 year-long Monitoring of NGC 5548
Zucker, S.; Bon, E.; Netzer, H. +14 more
We present an analysis of 43 years (1972 to 2015) of spectroscopic observations of the Seyfert 1 galaxy NGC 5548. This includes 12 years of new unpublished observations (2003 to 2015). We compiled about 1600 Hβ spectra and analyzed the long-term spectral variations of the 5100 Å continuum and the Hβ line. Our analysis is based on standard procedur…
The global surface composition of 67P/CG nucleus by Rosetta/VIRTIS. (I) Prelanding mission phase
Longobardo, Andrea; Palomba, Ernesto; Piccioni, Giuseppe +27 more
From August to November 2014 the Rosetta orbiter has performed an extensive observation campaign aimed at the characterization of 67P/CG nucleus properties and to the selection of the Philae landing site. The campaign led to the production of a global map of the illuminated portion of 67P/CG nucleus. During this prelanding phase the comet's helioc…
Chemical differentiation in a prestellar core traces non-uniform illumination
Caselli, P.; Spezzano, S.; Harju, J. +2 more
Dense cloud cores present chemical differentiation because C- and N-bearing molecules are distributed differently, the latter being less affected by freeze-out onto dust grains. In this letter we show that two C-bearing molecules, CH3OH and c-C3H2, present a strikingly different (complementary) morphology while sho…