Search Publications
The southern hemisphere of 67P/Churyumov-Gerasimenko: Analysis of the preperihelion size-frequency distribution of boulders ≥7 m
Bertaux, Jean-Loup; Da Deppo, Vania; Naletto, Giampiero +52 more
Aims: We calculate the size-frequency distribution of the boulders on the southern hemisphere of comet 67P Churyumov-Gerasimenko (67P), which was in shadow before the end of April 2015. We compare the new results with those derived from the northern hemisphere and equatorial regions of 67P, highlighting the possible physical processes that le…
The INTEGRAL/IBIS AGN catalogue: an update
Bird, A. J.; Ubertini, P.; Landi, R. +4 more
In the most recent IBIS survey based on observations performed during the first 1000 orbits of INTEGRAL, are listed 363 high-energy emitters firmly associated with AGN, 107 of which are reported here for the first time. We have used X-ray data to image the IBIS 90 per cent error circle of all the AGN in the sample of 107, in order to obtain the co…
SHIELD: Comparing Gas and Star Formation in Low-mass Galaxies
McQuinn, Kristen B. W.; Cannon, John M.; Skillman, Evan D. +22 more
We analyze the relationships between atomic, neutral hydrogen (H I) and star formation (SF) in the 12 low-mass SHIELD galaxies. We compare high spectral (∼0.82 km s-1 ch-1) and spatial resolution (physical resolutions of 160-640 pc) H I imaging from the VLA with Hα and far-ultraviolet imaging. We quantify the degree of co-spa…
Discovery of spin-up in the X-ray pulsar companion of the hot subdwarf HD 49798
Pintore, Fabio; Mereghetti, Sandro; Esposito, Paolo +4 more
The hot subdwarf HD 49798 has an X-ray emitting compact companion with a spin-period of 13.2 s and a dynamically measured mass of 1.28 ± 0.05 M⊙, consistent with either a neutron star or a white dwarf. Using all the available XMM-Newton and Swift observations of this source, we could perform a phase-connected timing analysis extending b…
Distant activity of 67P/Churyumov-Gerasimenko in 2014: Ground-based results during the Rosetta pre-landing phase
Faggi, Sara; Tubiana, Cecilia; Guilbert-Lepoutre, Aurélie +14 more
Context. As the ESA Rosetta mission approached, orbited, and sent a lander to comet 67P/Churyumov-Gerasimenko in 2014, a large campaign of ground-based observations also followed the comet.
Aims: We constrain the total activity level of the comet by photometry and spectroscopy to place Rosetta results in context and to understand the large-sc…
Powerful Activity in the Bright Ages. I. A Visible/IR Survey of High Redshift 3C Radio Galaxies and Quasars
Macchetto, F. D.; Capetti, A.; Sparks, W. B. +10 more
We present new rest-frame UV and visible observations of 22 high-z (1 < z < 2.5) 3C radio galaxies and QSOs obtained with the Hubble Space Telescope's Wide Field Camera 3 instrument. Using a custom data reduction strategy in order to assure the removal of cosmic rays, persistence signal, and other data artifacts, we have produced high-qualit…
A SINFONI view of the nuclear activity and circumnuclear star formation in NGC 4303
Colina, L.; Storchi-Bergmann, T.; Riffel, Rogemar A. +8 more
We present new maps of emission-line flux distributions and kinematics in both ionized (traced by H I and [Fe II] lines) and molecular (H2) gas of the inner 0.7 × 0.7 kpc2 of the galaxy NGC 4303, with a spatial resolution 40-80 pc and velocity resolution 90-150 km s- 1 obtained from near-IR integral field spectrosc…
The fossil wind structures of Eta Carinae: changes across one 5.54-yr cycle
Hamaguchi, Kenji; Corcoran, Michael; Moffat, Anthony F. J. +11 more
Eta Carinae, the closest, active, massive binary containing a highly unstable Luminous Blue Variable, exhibits expanding, compressed wind shells, seen in emission, that are spatially and spectrally resolved by Hubble Space Telescope/Space Telescope Imaging Spectrograph. Starting in 2009 June, these structures were mapped across its 5.54-yr, highly…
The spectroscopic imprint of the pre-eruptive configuration resulting into two major coronal mass ejections
Gontikakis, C.; Patsourakos, S.; Tsinganos, K. +1 more
Aims: We present a spectroscopic analysis of the pre-eruptive configuration of active region NOAA 11429, prior to two very fast coronal mass ejections (CMEs) on March 7, 2012 that are associated with this active region. We study the thermal components and the dynamics associated with the ejected flux ropes.
Methods: Using differential em…
Interaction of ULF waves with different ion species: Pitch angle and phase space density implications
Zong, Q. G.; Rankin, R.; Wang, Y. F. +2 more
ULF waves can accelerate/decelerate the charged particles including the ring current ions via drift-bounce resonance, which play an important role in the dynamics of ring current during storm times. This study compares the different behaviors of oxygen ions (10.5-35.1 keV) and protons (0.3-12.3 keV) which simultaneously interact with Pc5 ULF waves…