Search Publications
A Search for Star-Disk Interaction among the Strongest X-ray Flaring Stars in the Orion Nebula Cluster
Stassun, Keivan G.; Matt, Sean P.; Aarnio, Alicia N.
The Chandra Orion Ultradeep Project observed hundreds of young, low-mass stars undergoing highly energetic X-ray flare events. The 32 most powerful cases have been previously modeled with the result that the magnetic structures responsible for these flares can be many stellar radii in extent. In this paper, we model the observed spectral energy di…
Mid-infrared spectra of the shocked Murchison CM chondrite: Comparison with astronomical observations of dust in debris disks
Koike, C.; Mann, I.; Morlok, A. +2 more
We present laboratory mid-infrared transmission/absorption spectra obtained from matrix of the hydrated Murchison CM meteorite experimentally shocked at peak pressures of 10-49 GPa, and compare them to astronomical observations of circumstellar dust in different stages of the formation of planetary systems. The laboratory spectra of the Murchison …
Cassini INMS observations of neutral molecules in Saturn's E-ring
McNutt, Ralph L.; Mitchell, Donald G.; Waite, J. Hunter +6 more
In 2008, the Cassini ion neutral mass spectrometer (INMS) investigation made in situ measurements of neutral species near Saturn's equatorial plane within 0.5 Saturn radii (RS) of the orbit of Enceladus. After removing the large background and modeling to interpret instrumental effects, the data provide rough constraints on the neutral …
A characterization of the NGC 4051 soft X-ray spectrum as observed by XMM-Newton
Bianchi, S.; Guainazzi, M.; Santos-Lleo, M. +3 more
Context. Soft X-ray high resolution spectroscopy of obscured AGNs shows a complex soft X-ray spectrum dominated by emission lines of He and H-like transitions of elements from carbon to neon, as well as L-shell transitions due to iron ions.
Aims: In this paper we characterize the XMM-Newton RGS spectrum of the Seyfert 1 galaxy NGC 4051 observ…
A few days before the end of the 2008 extreme outburst of EX Lupi: accretion shocks and a smothered stellar corona unveiled by XMM-Newton
Hamaguchi, K.; Grosso, N.; Kastner, J. H. +2 more
Context. EX Lup is a pre-main sequence star that exhibits repetitive and irregular optical outbursts driven by an increase in the mass accretion rate in its circumstellar disk. In mid-January 2008, EX Lup, the prototype of the small class of eruptive variables called EXors, began an extreme outburst that lasted seven months.
Aims: We attempt …
Testing PDR models against ISO fine structure line data for extragalactic sources
Barlow, M. J.; Bell, T. A.; Viti, S. +2 more
Far-infrared [CII] 158-µm, [OI] 145-µm and [OI] 63-µm fine structure emission-line fluxes were measured from archival Infrared Space Observatory Long Wavelength Spectrometer spectra of 46 extragalactic sources, with 28 sources providing detections in all three lines. For 12 of the sources, the contribution to the [CII] 158-µ…
Herschel-PACS far-infrared photometry of two z > 4 quasars
Meisenheimer, K.; Jean, C.; Walter, F. +14 more
We present Herschel far-infrared (FIR) observations of two sub-mm bright quasars at high redshift: SDSS J1148+5251 (z = 6.42) and BR 1202-0725 (z = 4.69) obtained with the PACS instrument. Both objects are detected in the PACS photometric bands. The Herschel measurements provide additional data points that constrain the FIR spectral energy distrib…
Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei
Siana, Brian; Norris, Ray P.; Huynh, Minh T. +1 more
Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 µm) from a number of Legacy su…
Investigations of the sensitivity of a coronal mass ejection model (ENLIL) to solar input parameters
Odstrcil, D.; Vršnak, B.; Hesse, M. +3 more
Understanding space weather is not only important for satellite operations and human exploration of the solar system but also to phenomena here on Earth that may potentially disturb and disrupt electrical signals. Some of the most violent space weather effects are caused by coronal mass ejections (CMEs), but in order to predict the caused effects,…
Oscillations in a network region observed in the Hα line and their relation to the magnetic field
Georgoulis, M. K.; Tziotziou, K.; Tsiropoula, G. +1 more
Aims: Our aim is to gain a better understanding of the interaction between acoustic oscillations and the small-scale magnetic fields of the Sun. To this end, we examine the oscillatory properties of a network region and their relation to the magnetic configuration of the chromosphere. We link the oscillatory properties of a network region and…