Search Publications
Mean-flux-regulated Principal Component Analysis Continuum Fitting of Sloan Digital Sky Survey Lyα Forest Spectra
Spergel, David N.; Suzuki, Nao; Lee, Khee-Gan
Continuum fitting is an important aspect of Lyα forest science, since errors in the derived optical depths scale with the fractional continuum error. However, traditional methods of estimating continua in noisy and moderate-resolution spectra (e.g., Sloan Digital Sky Survey, SDSS; S/N <~ 10 pixel-1 and R ~ 2000), such as power-law ex…
The missing link: a low-mass X-ray binary in M31 seen as an ultraluminous X-ray source
Done, Chris; Middleton, Matthew J.; Sutton, Andrew D. +2 more
A new, transient ultraluminous X-ray source (ULX) was recently discovered by Chandra in M31 with a luminosity at ∼5 × 1039 erg s-1. Here we analyse a series of five subsequent XMM-Newton observations. These show a steady decline in X-ray luminosity over 1.5 months, from 1.8 × 1039 to 0.6 × 1039 erg s
A Spitzer MIPS Study of 2.5-2.0 M ⊙ Stars in Scorpius-Centaurus
Chen, Christine H.; Mamajek, Eric E.; Su, Kate Y. L. +2 more
We have obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 µm and 70 µm observations of 215 nearby, Hipparcos B- and A-type common proper-motion single and binary systems in the nearest OB association, Scorpius-Centaurus. Combining our MIPS observations with those of other ScoCen stars in the literature…
Detection of warm water vapour in Taurus protoplanetary discs by Herschel
Pinte, C.; Ménard, F.; Dent, W. R. F. +12 more
Line spectra of 68 Taurus T Tauri stars were obtained with the Herschel-PACS (Photodetector Array Camera and Spectrometer) instrument as part of the GASPS (GAS evolution in Protoplanetary Systems) survey of protoplanetary discs. A careful examination of the linescans centred on the [OI] 63.18 µm fine-structure line unveiled a line at 63.32 &…
Three-dimensional ray tracing of fast magnetosonic waves
Xiao, Fuliang; Zhou, Qinghua; He, Zhaoguo +1 more
A three dimensional ray tracing of fast magnetosonic (MS) waves is first performed by using a global core density model and a field-aligned density model. Simulating results show that MS waves are primarily confined within a few degrees of the geomagnetic equator due to magnetospheric reflection. MS waves originating from different L-shells on the…
Chandra High-resolution observations of CID-42, a Candidate Recoiling Supermassive Black Hole
Salvato, M.; Vignali, C.; Gilli, R. +15 more
We present Chandra High Resolution Camera observations of CID-42, a candidate recoiling supermassive black hole (SMBH) at z = 0.359 in the COSMOS survey. CID-42 shows two optical compact sources resolved in the HST/ACS image embedded in the same galaxy structure and a velocity offset of ~1300 km s-1 between the Hβ broad and narrow emiss…
Automatic Detection and Tracking of Coronal Mass Ejections. II. Multiscale Filtering of Coronagraph Images
Morgan, Huw; Gallagher, Peter T.; Habbal, Shadia R. +1 more
Studying coronal mass ejections (CMEs) in coronagraph data can be challenging due to their diffuse structure and transient nature, and user-specific biases may be introduced through visual inspection of the images. The large amount of data available from the Solar and Heliospheric Observatory (SOHO), Solar TErrestrial RElations Observatory (STEREO…
X-Ray Observations of the Supernova Remnant W28 with Suzaku. I. Spectral Study of the Recombining Plasma
Koyama, Katsuji; Sawada, Makoto
We present Suzaku results of the mixed-morphology supernova remnant W 28. The X-ray spectra of the central region of W 28 exhibit many bright emission lines from highly ionized atoms. An optically thin thermal plasma in collisional ionization equilibrium, either of single temperature or multi temperatures, failed to reproduce the data with line-li…
Herschel far-infrared observations of the Carina Nebula complex. I. Introduction and global cloud structure
Preibisch, T.; Roccatagliata, V.; Gaczkowski, B. +1 more
Context. The Carina Nebula represents one of the most massive star forming regions known in our Galaxy and displays a high level of feedback from the large number of very massive stars. While the stellar content is now well known from recent deep X-ray and near-infrared surveys, the properties of the clouds remained rather poorly studied until tod…
Radiation-driven winds of hot luminous stars XVI. Expanding atmospheres of massive and very massive stars and the evolution of dense stellar clusters
Pauldrach, A. W. A.; Hoffmann, T. L.; Vanbeveren, D.
Context. Starbursts play an essential role in the evolution of galaxies. In these environments, massive stars, with their short lifetimes, are of particular importance. The stellar winds of massive stars significantly influence not only on their surroundings, but the associated mass loss also profoundly affects the evolution of the stars themselve…