Search Publications
The awakening beast in the Seyfert 1 Galaxy KUG 1141+371 - I
Ho, Luis C.; Steiner, James F.; Fabian, Andrew C. +10 more
KUG 1141+371 is a Seyfert 1 galaxy that shows a simultaneous flux increase in the optical and UV bands in the past decade. For instance, the latest Swift observation in 2019 shows that the UVW2 flux of the active galactic nucleus in KUG 1141+371 has increased by over one order of magnitude since 2009. Meanwhile, the soft X-ray flux of KUG 1141+371…
H2 molecular gas absorption-selected systems trace CO molecular gas-rich galaxy overdensities
Lopez, Sebastian; Péroux, Céline; De Cia, Annalisa +3 more
Absorption-selected galaxies offer an effective way to study low-mass galaxies at high redshift. However, the physical properties of the underlying galaxy population remain uncertain. In particular, the multiphase circumgalactic medium is thought to hold key information on gas flows into and out of galaxies that are vital for galaxy evolution mode…
The infrared excess emission from nearby Gaia DR2 M dwarfs
Song, Inseok; Sgro, Lauren A.
We use Gaia DR2 data to search for M dwarfs with infrared (IR) excess, within 100 pc. By cross-matching Gaia with AllWISE and 2MASS catalogues, we select a subset of K/M dwarfs with reliable photometric data in both the optical and near-to-mid IR. Using our SED fitting pipeline, we determine a photospheric model for each star and determine its sig…
Limits on the presence of planets in systems with debris discs: HD 92945 and HD 107146
Henning, T.; Messina, S.; D'Orazi, V. +38 more
Recent observations of resolved cold debris discs at tens of au have revealed that gaps could be a common feature in these Kuiper-belt analogues. Such gaps could be evidence for the presence of planets within the gaps or closer in near the edges of the disc. We present SPHERE observations of HD 92945 and HD 107146, two systems with detected gaps. …
The BIG X-ray tail
Churazov, Eugene; Jones, Christine; Fossati, Matteo +9 more
Galaxy clusters grow primarily through the continuous accretion of group-scale haloes. Group galaxies experience preprocessing during their journey into clusters. A star-bursting compact group, the Blue Infalling Group (BIG), is plunging into the nearby cluster A1367. Previous optical observations reveal rich tidal features in the BIG members, and…
IKT 16 aka PSR J0058-7218: discovery of a 22 ms energetic rotation-powered pulsar in the Small Magellanic Cloud
Haberl, F.; Tiengo, A.; Filipović, M. D. +5 more
We report here on the discovery with XMM-Newton of pulsations at 22 ms from the central compact source associated with IKT 16, a supernova remnant in the Small Magellanic Cloud (SMC). The measured spin period and spin period derivative correspond to 21.7661076(2) ms and 2.9(3) × 10-14 s s-1, respectively. Assuming standard sp…
The 2017 May 20 stellar occultation by the elongated centaur (95626) 2002 GZ32
Mottola, S.; Charmandaris, V.; Alvarez-Candal, A. +56 more
We predicted a stellar occultation of the bright star Gaia DR1 4332852996360346368 (UCAC4 385-75921) (mV = 14.0 mag) by the centaur 2002 GZ32 for 2017 May 20. Our latest shadow path prediction was favourable to a large region in Europe. Observations were arranged in a broad region inside the nominal shadow path. Series of ima…
NGTS and HST insights into the long-period modulation in GW Librae
Reichart, D. E.; Hermes, J. J.; Gänsicke, B. T. +17 more
Light curves of the accreting white dwarf pulsator GW Librae spanning a 7.5-month period in 2017 were obtained as part of the Next-Generation Transit Survey. This data set comprises 787 h of photometry from 148 clear nights, allowing the behaviour of the long (hours) and short-period (20 min) modulation signals to be tracked from night to night ov…
Ultraviolet Imaging Telescope (UVIT) observation of the Galactic globular cluster NGC 7492
Pradhan, Ananta C.; Mohapatra, Abhisek; Parthasarathy, M. +4 more
We present detailed photometric observations of the Galactic globular cluster NGC 7492 using the data obtained with two far-ultraviolet (FUV; 1300-1800 Å) and three near-ultraviolet (NUV; 2000-3000 Å) filters of Ultraviolet Imaging Telescope (UVIT) onboard the AstroSat satellite. We confirmed the cluster membership of the extracted sources using G…
Star cluster survival in dark matter haloes: an old cluster in Eridanus II?
Alzate, Jairo A.; Bruzual, Gustavo; Lomelí-Núñez, Luis +2 more
The star formation history and the internal dynamics of Milky Way satellite galaxies are often complicated. In the last years, a substantial fraction of the known faint dwarf satellites have been studied. Some of them show embedded stellar substructures, such as star clusters and even globular star clusters. In this work, we study Eridanus II, a d…