Search Publications
Probing the unidentified Fermi blazar-like population using optical polarization and machine learning
Blinov, D.; Liodakis, I.
The Fermi γ-ray space telescope has revolutionized our view of the γ-ray sky and the high-energy processes in the Universe. While the number of known γ-ray emitters has increased by orders of magnitude since the launch of Fermi, there is an ever increasing number of, now more than a thousand, detected point sources whose low-energy counterpart is …
Detection of metal-rich, cool-warm gas in the outskirts of galaxy clusters
Charlton, Jane C.; Nagai, Daisuke; Pradeep, Jayadev +3 more
We present an ultraviolet quasar absorption line analysis of metal lines associated with three strong intervening H I absorbers (with N(H I) > 1016.5 cm-2) detected in the outskirts of Sunyaev-Zel'dovich (SZ) effect-selected galaxy clusters (zcl ∼ 0.4-0.5), within clustocentric impact parameters of ρcl
A universal relation of dust obscuration across cosmic time
Zheng, Xian Zhong; Wuyts, Stijn; Pan, Zhizheng +2 more
We investigate dust obscuration as parametrized by the infrared excess IRX ≡ LIR/LUV in relation to global galaxy properties, using a sample of ∼32 000 local star-forming galaxies (SFGs) selected from SDSS (Sloan Digital Sky Survey), GALEX (Galaxy Evolution Explorer), and WISE (Wide-field Infrared Survey Explorer). We show th…
Circumstellar CO in metal-poor stellar winds: the highly irradiated globular cluster star 47 Tucanae V3
Zijlstra, A. A.; Richards, A. M. S.; Boyer, M. L. +4 more
We report the first detection of circumstellar CO in a globular cluster. Observations with ALMA have detected the CO J = 3-2 and SiO v = 1 J = 8 - 7 transitions at 345 and 344 GHz, respectively, around V3 in 47 Tucanae (NGC 104; [Fe/H] = -0.72 dex), a star on the asymptotic giant branch. The CO line is detected at 7σ at a rest velocity vLSR
CRTS J035010.7 + 323230, a new eclipsing polar in the cataclysmic variable period gap
Szkody, Paula; Mason, Paul A.; Wells, Natalie K. +2 more
We report the discovery of a new eclipsing polar, CRTS J035010.7+323230 (hereafter CRTS J0350+3232). We identified this cataclysmic variable (CV) candidate as a possible polar from its multiyear Catalina Real-Time Transient Survey (CRTS) optical light curve. Photometric monitoring of 22 eclipses in 2015 and 2017 was performed with the 2.1-m Otto S…
A young and obscured AGN embedded in the giant radio galaxy Mrk 1498
Jiménez-Andrade, E. F.; Ubertini, P.; Chavushyan, V. +10 more
Mrk 1498 is part of a sample of galaxies with extended emission-line regions (extended outwards up to a distance of ∼7 kpc) suggested to be photoionized by an AGN that has faded away or that is still active but heavily absorbed. Interestingly, the nucleus of Mrk 1498 is at the centre of two giant radio lobes with a projected linear size of 1.1 Mpc…
Evidence of a large-scale positive rotation-metallicity correlation in the Galactic thick disc
Lattanzi, Mario G.; Re Fiorentin, Paola; Spagna, Alessandro
This study is based on high quality astrometric and spectroscopic data from the most recent releases by Gaia and APOGEE. We select 58 882 thin and thick disc red giants in the Galactocentric (cylindrical) distance range 5 < R < 13 kpc and within |z| < 3 kpc, for which full chemo-kinematical information is available. Radial chemical gradie…
The multi-outburst activity of the magnetar in Westerlund I
Campana, S.; Tiengo, A.; Götz, D. +17 more
After two major outbursts in 2006 and 2011, on 2017 May 16 the magnetar CXOU J164710.2-455216, hosted within the massive star cluster Westerlund I, emitted a short (∼20 ms) burst, which marked the onset of a new active phase. We started a long-term monitoring campaign with Swift (45 observations), Chandra (five observations), and NuSTAR (four obse…
On the diagnostic power of FIR/sub-mm SED fitting in massive galactic molecular clumps
Pitts, Rebecca L.; Barnes, Peter J.; Varosi, Frank
We used far-infrared (FIR) and sub-millimetre continuum data from Herschel and the Atacama Pathfinder EXperiment (APEX) to fit pixel-by-pixel modified Planck spectral energy distributions to prestellar and protostellar clumps in the Census of High- and Medium-mass Protostars (CHaMP) (280° < ℓ < 300°, -4° < b < +2°). We present maps of …
Swift X-ray and UV observations of SDSS J141118.31+481257.6 during its first ever recorded superoutburst
Maccarone, T. J.; Rivera Sandoval, L. E.
SDSS J141118.31+481257.6 is an ultracompact white dwarf binary (or AM CVn system) with an orbital period of 46 min. We analyse ∼23 ks of X-ray and ultraviolet (UV) data taken with the Neil Gehrels Swift Observatory during its first ever recorded outbursts. The events took place 13 yr after the system was discovered. We detected three events in our…