Search Publications
The clustering amplitude of X-ray-selected AGN at z ∼ 0.8: evidence for a negative dependence on accretion luminosity
Georgakakis, A.; Salvato, M.; Liu, Z. +5 more
The northern tile of the wide-area and shallow XMM-XXL X-ray survey field is used to estimate the average dark matter halo mass of relatively luminous X-ray-selected active galactic nucleus (AGN) [log {L}_X (2-10 keV)= 43.6^{+0.4}_{-0.4} erg s^{-1}] in the redshift interval z = 0.5-1.2. Spectroscopic follow-up observations of X-ray sources in the …
Radiative energy balance of Venus based on improved models of the middle and lower atmosphere
Kappel, D.; Drossart, P.; Piccioni, G. +4 more
The distribution of sources and sinks of radiative energy forces the atmospheric dynamics. The radiative transfer simulation model described by Haus et al. (2015b) is applied to calculate fluxes and temperature change rates in the middle and lower atmosphere of Venus (0-100 km) covering the energetic significant spectral range 0.125-1000 µm.…
Dynamics of the flares in the active polar region of Jupiter
Badman, S. V.; Bonfond, B.; Gérard, J. -C. +2 more
The duskside of the polar region of Jupiter's UV aurorae, called the active region, sometimes exhibits quasiperiodic (QP) flares on timescales of 2-3 min. Based on Hubble Space Telescope Far-UV time-tag images, we show for the first time that the Northern Hemisphere also displays QP flares. The area covered by these flares can reach up to 2.4 × 10…
[Fe II] jets from intermediate-mass protostars in Carina
Smith, Nathan; Bally, John; Reiter, Megan
We present new HST/WFC3-IR narrow-band [Fe II] images of protostellar jets in the Carina Nebula. Combined with five previously published sources, we have a sample of 18 jets and two Herbig-Haro (HH) objects. All of the jets we targeted with Wide-Field Camera 3 (WFC3) show bright infrared [Fe II] emission, and a few Hα candidate jets are confirmed …
Saturn's tropospheric particles phase function and spatial distribution from Cassini ISS 2010-11 observations
Irwin, Patrick G. J.; Sánchez-Lavega, Agustín; Pérez-Hoyos, Santiago +2 more
The phase function describes the way particles scatter the incoming radiation. This is a fundamental piece of knowledge in order to understand how a planetary atmosphere scatters sunlight and so it has a profound influence in the retrieved atmospheric properties such as cloud height, particle density distribution and radiative forcing by aerosols.…
The origin of seed photons for Comptonization in the black hole binary Swift J1753.5-0127
Tsygankov, S.; Neustroev, V.; Veledina, A. +1 more
Aims: The black hole binary Swift J1753.5-0127 is providing a unique data set to study accretion flows. Various investigations of this system and of other black holes have not, however, led to an agreement on the accretion flow geometry or on the seed photon source for Comptonization during different stages of X-ray outbursts. We place constr…
Oscillatory Response of the Solar Chromosphere to a Strong Downflow Event above a Sunspot
Chae, Jongchul; Song, Donguk; Madjarska, Maria S. +3 more
We report three-minute oscillations in the solar chromosphere driven by a strong downflow event in a sunspot. We used the Fast Imaging Solar Spectrograph of the 1.6 m New Solar Telescope and the Interface Region Imaging Spectrograph (IRIS). The strong downflow event is identified in the chromospheric and transition region lines above the sunspot u…
Disc colours in field and cluster spiral galaxies at 0.5 ≲z ≲ 0.8
Aragón-Salamanca, Alfonso; Zaritsky, Dennis; Jablonka, Pascale +9 more
We present a detailed study of the colours of late-type galaxy discs for ten of the EDisCS galaxy clusters with 0.5 ≲ z ≲ 0.8. Our cluster sample contains 172 spiral galaxies, and our control sample is composed of 96 field disc galaxies. We deconvolved their ground-based V and I images obtained with FORS2 at the VLT with initial spatial resolution…
High-resolution mapping of dust via extinction in the M31 bulge
Lauer, Tod R.; Wang, Q. D.; Dalcanton, Julianne J. +5 more
We map the dust distribution in the central 180 arcsec (∼680 pc) region of the M31 bulge, based on HST WFC3 and ACS observations in ten bands from near-ultraviolet (2700 Å) to near-infrared (1.5 µm). This large wavelength coverage gives us great leverage to detect not only dense dusty clumps, but also diffuse dusty molecular gas. We fit a pi…
A multi-scale magnetotail reconnection event at Saturn and associated flows: Cassini/UVIS observations
Jackman, C. M.; Mitchell, D. G.; Jia, X. +6 more
We present high-resolution Cassini/UVIS (Ultraviolet Imaging Spectrograph) observations of Saturn's aurora during May 2013 (DOY 140-141). The observations reveal an enhanced auroral activity in the midnight-dawn quadrant in an extended local time sector (∼02 to 05 LT), which rotates with an average velocity of ∼45% of rigid corotation. The auroral…