Search Publications

The Galactic Center in the Far-infrared

Smith, Howard A.; Stark, A. A.; González-Alfonso, E. +2 more

We analyze the far-infrared dust emission from the Galactic center region, including the circumnuclear disk (CND) and other structures, using Herschel PACS and SPIRE photometric observations. These Herschel data are complemented by unpublished observations by the Infrared Space Observatory Long Wavelength Spectrometer (ISO-LWS), which used paralle…

Impact factor for the ionospheric total electron content response to solar flare irradiation

Zhang, W.; Cai, L.; Zhang, D. H. +4 more

On the basis of ionospheric total electron content (TEC) enhancement over the subsolar region during flares, and combined with data of the peak X-ray flux in the 0.1-0.8 nm region, EUV increase in the 0.1-50 and 26-34 nm regions observed by the SOHO Solar EUV Monitor EUV detector, also with the flare location on the solar disc, the relationship am…

Measurements and modelling of high pressure pure CO₂ spectra from 750 to 8500 cm^-1. I—central and wing regions of the allowed vibrational bands

Piccioni, G.; Snels, M.; Tran, H. +2 more

X-Ray Activity Phased with Planet Motion in HD 189733?

Günther, H. M.; Pillitteri, I.; Cohen, O. +2 more

We report on the follow-up XMM-Newton observation of the planet-hosting star HD 189733 we obtained in 2011 April. We observe a flare just after the secondary transit of the hot Jupiter. This event shares the same phase and many of the characteristics of the flare we observed in 2009. We suggest that a systematic interaction between planet and stel…

Galaxy properties in different environments up to z∼ 3 in the GOODS NICMOS Survey

Conselice, Christopher J.; Bluck, Asa F. L.; Mortlock, Alice +4 more

We study the relationship between galaxy colour, stellar mass and local galaxy density in a deep near-infrared imaging survey up to a redshift of z∼ 3 using the GOODS (Great Observatories Origins Deep Survey) NICMOS (Near Infrared Camera and Multi-Object Spectrometer) Survey (GNS). The GNS is a deep near-infrared Hubble Space Telescope survey imag…

Variable X-ray absorption in the mini-BAL QSO PG 1126-041

Cappi, M.; Ponti, G.; Vignali, C. +7 more

Context. X-ray studies of active galactic nuclei (AGN) with powerful nuclear winds are important for constraining the physics of the inner accretion/ejection flow around supermassive black holes (SMBHs) and for understanding the impact of such winds on the AGN environment.
Aims: Our main scientific goal is to constrain the properties of the c…

Suprathermal electron acceleration during reconnection onset in the magnetotail

André, M.; Vaivads, A.; Khotyaintsev, Yu. V. +1 more

We study one event of reconnection onset associated to a small substorm on 27 September 2006 by using Cluster observations at inter-spacecraft separation of about 10 000 km. We focus on the acceleration of suprathermal electrons during different stages of reconnection. We show that several distinct stages of acceleration occur: (1) moderate accele…

Suzaku Studies of Wide-Band Spectral Variability of the Bright Type I Seyfert Galaxy Markarian 509

Makishima, Kazuo; Nakazawa, Kazuhiro; Yamada, Shin'ya +3 more

The Type I Seyfert galaxy Markarian 509 was observed with Suzaku in 2010 November, for a gross time span of 2.2 days. The timing and spectral properties of the 0.5-45 keV X-rays, detected with the XIS and HXD, consistently revealed the presence of a soft spectral component that remained constant while the total X-ray intensity varied by

The 22 May 2007 B-class flare: new insights from Hinode observations

Mason, H. E.; Del Zanna, G.; Bradshaw, S. J. +2 more

We present multi-wavelength observations of a small B-class flare which occurred on the Sun on 2007 May 22. The observations include data from Hinode, GOES, TRACE and the Nobeyama Radioheliograph. We obtained spatially and spectrally-resolved information from the Hinode EUV Imaging Spectrometer (EIS) during this event. The temporal and temperature…

The Carbon Monoxide Abundance in Comet 103P/Hartley 2 During the EPOXI Flyby

Stern, S. A.; Feldman, P. D.; A'Hearn, M. F. +2 more

We report the detection of several emission bands in the CO Fourth Positive Group from comet 103P/Hartley 2 during ultraviolet spectroscopic observations from the Hubble Space Telescope on 2010 November 4 near the time of closest approach by NASA's EPOXI spacecraft. The derived CO/H₂O ratio is 0.15%-0.45%, which places 103P/Hartley 2 am…