Search Publications
Twist Accumulation and Topology Structure of a Solar Magnetic Flux Rope
Cheng, X.; Ding, M. D.; Guo, Y. +2 more
To study the buildup of a magnetic flux rope before a major flare and coronal mass ejection (CME), we compute the magnetic helicity injection, twist accumulation, and topology structure of the three-dimensional (3D) magnetic field, which is derived by the nonlinear force-free field model. The Extreme-ultraviolet Imaging Telescope on board the Sola…
Fossil Imprint of a Powerful Flare at the Galactic Center along the Magellanic Stream
Sutherland, Ralph S.; Bland-Hawthorn, J.; Maloney, Philip R. +1 more
The Fermi satellite discovery of the gamma-ray emitting bubbles extending 50° (10 kpc) from the Galactic center has revitalized earlier claims that our Galaxy has undergone an explosive episode in the recent past. We now explore a new constraint on such activity. The Magellanic Stream is a clumpy gaseous structure free of stars trailing behind the…
The XMM-Newton survey of the Small Magellanic Cloud: The X-ray point-source catalogue
Pietsch, W.; Haberl, F.; Hatzidimitriou, D. +8 more
Context. Local-Group galaxies provide access to samples of X-ray source populations of whole galaxies. The XMM-Newton survey of the Small Magellanic Cloud (SMC) completely covers the bar and eastern wing with a 5.6 deg2 area in the (0.2-12.0) keV band.
Aims: To characterise the X-ray sources in the SMC field, we created a catalogue…
Physical Properties of Spectroscopically Confirmed Galaxies at z >= 6. II. Morphology of the Rest-frame UV Continuum and Lyα Emission
Ouchi, Masami; Shimasaku, Kazuhiro; Fan, Xiaohui +8 more
We present a detailed structural and morphological study of a large sample of spectroscopically confirmed galaxies at z >= 6 using deep Hubble Space Telescope (HST) near-IR broad-band images and Subaru Telescope optical narrow-band images. The galaxy sample consists of 51 Lyα emitters (LAEs) at z ~= 5.7, 6.5, and 7.0, and 16 Lyman break galaxie…
The chemistry of ions in the Orion Bar I. - CH+, SH+, and CF+. The effect of high electron density and vibrationally excited H2 in a warm PDR surface
Le Bourlot, J.; Le Petit, F.; Ossenkopf, V. +8 more
Context. The abundances of interstellar CH+ and SH+ are not well understood as their most likely formation channels are highly endothermic. Several mechanisms have been proposed to overcome the high activation barriers, including shocks, turbulence, and H2 vibrational excitation.
Aims: Using data from the Hers…
Comprehensive study of a z = 2.35 DLA Galaxy: mass, metallicity, age, morphology and SFR from HST and VLT
Pettini, Max; Noterdaeme, Pasquier; Gallazzi, Anna +8 more
We present a detailed study of the emission from a z = 2.35 galaxy that causes damped Lyman α absorption in the spectrum of the background quasar (QSO), SDSS J2222-0946. We present the results of extensive analyses of the stellar continuum covering the rest frame optical-UV regime based on broad-band Hubble Space Telescope (HST) imaging, and of sp…
Evidence for a correlation between the sizes of quiescent galaxies and local environment to z ∼ 2
Grogin, Norman A.; Kocevski, Dale D.; Koekemoer, Anton M. +14 more
We present evidence for a strong relationship between galaxy size and environment for the quiescent population in the redshift range 1 < z < 2. Environments were measured using projected galaxy overdensities on a scale of 400 kpc, as determined from ∼96 000 K-band-selected galaxies from the UKIDSS Ultra Deep Survey (UDS). Sizes were determin…
The Rise of an Ionized Wind in the Narrow-line Seyfert 1 Galaxy Mrk 335 Observed by XMM-Newton and HST
Kriss, G. A.; Ely, J.; Komossa, S. +6 more
We present the discovery of an outflowing ionized wind in the Seyfert 1 galaxy Mrk 335. Despite having been extensively observed by most of the largest X-ray observatories in the last decade, this bright source was not known to host warm absorber gas until recent XMM-Newton observations in combination with a long-term Swift monitoring program have…
Testing the Universality of the Fundamental Metallicity Relation at High Redshift Using Low-mass Gravitationally Lensed Galaxies
Richard, Johan; Ellis, Richard S.; Belli, Sirio +1 more
We present rest-frame optical spectra for a sample of nine low-mass star-forming galaxies in the redshift range 1.5 < z < 3 which are gravitationally lensed by foreground clusters. We used Triplespec, an echelle spectrograph at the Palomar 200 inch telescope that is very effective for this purpose as it samples the entire near-infrared spect…
X-Ray Properties of the Northern Galactic Cap Sources in the 58 Month Swift/BAT Catalog
Brandt, William N.; Mushotzky, Richard F.; Baumgartner, Wayne H. +5 more
We present a detailed X-ray spectral analysis of the non-beamed, hard X-ray selected active galactic nuclei (AGNs) in the northern Galactic cap of the 58 month Swift Burst Alert Telescope (Swift/BAT) catalog, consisting of 100 AGNs with b > 50°. This sky area has excellent potential for further dedicated study due to a wide range of multi-wavel…