Search Publications
Evidence for feedback in action from the molecular gas content in the z ~ 1.6 outflowing QSO XID2028
Lutz, D.; Daddi, E.; Maiolino, R. +16 more
Aims: Gas outflows are believed to play a pivotal role in shaping galaxies, as they regulate both star formation and black hole growth. Despite their ubiquitous presence, the origin and the acceleration mechanism of these powerful and extended winds is not yet understood. Direct observations of the cold gas component in objects with detected …
Hard X-ray polarimetry with Astrosat-CZTI
Rao, A. R.; Bhattacharya, D.; Vadawale, S. V. +5 more
X-ray polarimetry is largely an unexplored area of an otherwise mature field of X-ray astronomy. Except for a few early attempts during the 1970s, no dedicated X-ray polarimeter has been flown during the past four decades. On the other hand, the scientific value of X-ray polarization measurement has been well known for a long time, and there has b…
Record-breaking storm activity on Uranus in 2014
de Pater, Imke; Sromovsky, L. A.; Fry, P. M. +3 more
In spite of an expected decline in convective activity following the 2007 equinox of Uranus, eight sizable storms were detected on the planet with the near-infrared camera NIRC2, coupled to the adaptive optics system, on the 10-m W.M. Keck telescope on UT 5 and 6 August 2014. All storms were on Uranus' northern hemisphere, including the brightest …
The initial conditions of stellar protocluster formation - II. A catalogue of starless and protostellar clumps embedded in IRDCs in the Galactic longitude range 15° ≤ l ≤ 55°
Peretto, N.; Fuller, G. A.; Molinari, S. +2 more
We present a catalogue of starless and protostellar clumps associated with infrared dark clouds (IRDCs) in a 40° wide region of the inner Galactic plane (|b| ≤ 1°). We have extracted the far-infrared (FIR) counterparts of 3493 IRDCs with known distance in the Galactic longitude range 15° ≤ l ≤ 55° and searched for the young clumps using Herschel i…
Sixteen Years of Ulysses Interstellar Dust Measurements in the Solar System. I. Mass Distribution and Gas-to-dust Mass Ratio
Krüger, Harald; Grün, Eberhard; Sterken, Veerle J. +1 more
In the early 1990s, contemporary interstellar dust penetrating deep into the heliosphere was identified with the in situ dust detector on board the Ulysses spacecraft. Between 1992 and the end of 2007 Ulysses monitored the interstellar dust stream. The interstellar grains act as tracers of the physical conditions in the local interstellar medium (…
NuSTAR Hard X-Ray Survey of the Galactic Center Region I: Hard X-Ray Morphology and Spectroscopy of the Diffuse Emission
Hailey, Charles J.; Mori, Kaya; Giommi, Paolo +35 more
We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456-2901 into non-thermal X-ray filaments, molecular clouds, point sources, and a previously unknown central component of hard X-ray emission (CHXE). NuSTAR detects four non-thermal X-ray filaments, exte…
A Comprehensive Statistical Assessment of Star-Planet Interaction
Wright, Jason T.; Gallo, Elena; Miller, Brendan P. +1 more
We investigate whether magnetic interaction between close-in giant planets and their host stars produce observable statistical enhancements in stellar coronal or chromospheric activity. New Chandra observations of 12 nearby (d < 60 pc) planet-hosting solar analogs are combined with archival Chandra, XMM-Newton, and ROSAT coverage of 11 similar …
IC 3599 Did It Again: A Second Outburst of the X-Ray Transient Seyfert 1.9 Galaxy
Komossa, S.; Saxton, Richard; Grupe, Dirk
We report on the Swift discovery of a second high-amplitude (factor 100) outburst of the Seyfert 1.9 galaxy IC 3599, and discuss implications for outburst scenarios. Swift detected this active galactic nucleus (AGN) again in 2010 February in X-rays at a level of (1.50 ± 0.11) × {{10}36} W (0.2-2.0 keV), which is nearly as luminous as th…
The Origin of the Spurious Iron Spread in the Globular Cluster NGC 3201
Massari, D.; Mucciarelli, A.; Ferraro, F. R. +2 more
NGC 3201 is a globular cluster suspected to have an intrinsic spread in the iron content. We re-analyzed a sample of 21 cluster stars observed with UVES-FLAMES at the Very Large Telescope and for which Simmerer et al. found a 0.4 dex wide [Fe/H] distribution with a metal-poor tail. We confirmed that when spectroscopic gravities are adopted, the de…
Solar wind sputtering of dust on the surface of 67P/Churyumov-Gerasimenko
De Keyser, Johan; Gombosi, Tamas I.; Berthelier, Jean-Jacques +16 more
Aims: Far away from the Sun, at around 3 AU, the activity of comet 67P/Churyumov-Gerasimenko is low and changes with local time (solar insolation), with location (chemical heterogeneity of the surface), and with season. When the activity is very low because the total cross section of the comet against the Sun is small, the solar wind has acce…