Search Publications
The (Re)appearance of NGC 925 ULX-3, a New Transient ULX
Fürst, Felix; Middleton, Matthew J.; Roberts, Timothy P. +8 more
We report the discovery of a third ULX in NGC 925 (ULX-3), detected in 2017 November by Chandra at a luminosity of LX = (7.8 ± 0.8) × 1039 erg s-1. Examination of archival data for NGC 925 reveals that ULX-3 was detected by Swift at a similarly high luminosity in 2011, as well as by XMM-Newton in 2017 January at a …
Annual parallax measurement of the Mira variable star BX Camelopardalis with VERA
Kurayama, Tomoharu; Honma, Mareki; Nakagawa, Akiharu +8 more
We report the results of astrometric VLBI observations toward the Mira variable star BX Cam using the VERA VLBI array. The observation was performed from 2012 February to 2014 November. The parallax obtained is 1.73 ± 0.03 mas corresponding to a distance of 0.58 ± 0.01 kpc. The parallax of this source was reported in Gaia DR2 as 4.13 ± 0.25 mas, a…
Bi-abundance photoionization models of planetary nebulae: determining the amount of oxygen in the metal-rich component
Morisset, C.; Gómez-Llanos, V.
We study the hypothesis of high-metallicity clumps being responsible for the abundance discrepancy found in planetary nebulae between the values obtained from recombination and collisionally excited lines. We generate grids of photoionization models combining cold metal-rich clumps emitting the heavy element recombination lines, embedded in a norm…
Visible and near-infrared observations of interstellar comet 2I/Borisov with the 10.4-m GTC and the 3.6-m TNG telescopes
Geier, S.; Lara, L. M.; Moreno, F. +15 more
In this work, we present the results of an observational study of 2I/Borisov carried out with the 10.4-m Gran Telescopio Canarias (GTC) and the 3.6-m Telescopio Nazionale Galileo (TNG), both telescopes located at the Roque de Los Muchachos Observatory, in the island of La Palma (Spain). The study includes images in the visible and near-infrared, a…
In Search for a Planet Better than Earth: Top Contenders for a Superhabitable World
Heller, René; Guinan, Edward; Schulze-Makuch, Dirk
The fact that Earth is teeming with life makes it appear odd to ask whether there could be other planets in our galaxy that may be even more suitable for life. Neglecting this possible class of "superhabitable" planets, however, could be considered anthropocentric and geocentric biases. Most important from the perspective of an observer searching …
Informing dark matter direct detection limits with the ARTEMIS simulations
McCarthy, Ian G.; Font, Andreea S.; Poole-McKenzie, Robert +4 more
Dark matter (DM) direct detection experiments aim to place constraints on the DM-nucleon scattering cross-section and the DM particle mass. These constraints depend sensitively on the assumed local DM density and velocity distribution function. While astrophysical observations can inform the former (in a model-dependent way), the latter is not dir…
Dual AGN Candidates with Double-peaked [O III] Lines Matching that of Confirmed Dual AGNs
Kim, D. -C.; Momjian, E.; Kim, Minjin +3 more
We have performed a spectral decomposition to search for dual active galactic nuclei (DAGNs) in the Sloan Digital Sky Survey (SDSS) quasars with z < 0.25. Potential DAGN candidates are searched by referencing velocity offsets and spectral shapes of double-peaked [O III] lines of known DAGNs. Out of 1271 SDSS quasars, we have identified 77 DAGN …
Solar Electrons and Protons in the Events of September 4-10, 2017 and Related Phenomena
Logachev, Yu. I.; Struminskii, A. B.; Grigor'eva, I. Yu. +1 more
The solar proton events on September 4-10, 2017 motivated us to reconsider the hypothesis of the presence of two phases of acceleration of charged particles in solar flares in which nonrelativistic electrons are accelerated in the first phase, while relativistic electrons and protons are accelerated during the second phase. According to the data o…
The interior of Comet 67P/C-G; revisiting CONSERT results with the exact position of the Philae lander
Kofman, Wlodek; Herique, Alain; Rogez, Yves +3 more
CONSERT, a bistatic radar onboard the Rosetta spacecraft and its Philae lander, was designed to probe the nucleus of comet 67P/Churyumov-Gerasimenko with radio waves at 90 MHz frequency. In 2016 September, the exact position of Philae was retrieved, within the region previously identified by CONSERT. This allowed us to revisit the measurements and…
Radial Star Formation Histories in 32 Nearby Galaxies
Kobulnicky, Henry A.; Dale, Daniel A.; Cox, Isaiah S. +10 more
The spatially resolved star formation histories are studied for 32 normal star-forming galaxies drawn from the Spitzer Extended Disk Galaxy Exploration Science survey. At surface brightness sensitivities fainter than 28 mag arcsec-2, the new optical photometry is deep enough to complement archival ultraviolet and infrared imaging and to…