Search Publications
A Universal Decline Law of Classical Novae. III. GQ Muscae 1983
Cassatella, Angelo; Kato, Mariko; Hachisu, Izumi
We present a unified model of infrared (IR), optical, ultraviolet (UV), and X-ray light curves for the 1983 outburst of GQ Muscae (Nova Muscae 1983) and estimate its white dwarf (WD) mass. Based on an optically thick wind model of nova outbursts, we model the optical and IR light curves with free-free emission, and the UV 1455 Å and supersoft X-ra…
Deep Infrared Observations of the Puzzling Central X-Ray Source in RCW 103
Caraveo, P. A.; Bignami, G. F.; Mereghetti, S. +4 more
The object 1E 161348-5055 (1E 1613) is a pointlike, soft X-ray source shining at the center of the 2000 yr old supernova remnant (SNR) RCW 103. It features a puzzling 6.67 hr periodicity and dramatic variability over a timescale of a few years. This, coupled with a young age and the lack of an obvious optical counterpart, makes 1E 1613 a unique so…
Intermittency in the Photosphere and Corona above an Active Region
Wang, Haimin; Yurchyshyn, Vasyl; Abramenko, Valentyna
Recent studies have demonstrated without doubt that the magnetic field in the photosphere and corona is an intermittent structure, opening new views of the underlying physics. In particular, such problems as the existence in the corona of localized areas with extremely strong resistivity (required to explain magnetic reconnection at all scales) an…
Mid-Infrared Spectra of High-Redshift (z > 2) Radio Galaxies
Stern, D.; Fazio, G. G.; Seymour, N. +8 more
We present the first mid-infrared Spitzer/Infrared Spectrograph (IRS) observations of powerful radio galaxies at z > 2. These radio galaxies, 4C +23.56 (z = 2.48) and 6C J1908+7220 (z = 3.53), both show strong mid-infrared continua, but with 6C J1908+7220 also showing strong PAH emission at rest-frame 6.2 and 7.7 µm. In 4C +23.56 we see n…
On the Distance and Reddening of the Starburst Galaxy IC 10
Walker, A. R.; Prada Moroni, P. G.; Degl'Innocenti, S. +16 more
We present deep and accurate optical photometry of the Local Group starburst galaxy IC 10. The photometry is based on two sets of images collected with the Advanced Camera for Surveys and with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. We provide new estimates of the tip of the red giant branch (TRGB) magnitude, m{…
Physical Properties of the AXP 4U 0142+61 from X-Ray Spectral Analysis
Göğüş, Ersin; Güver, Tolga; Özel, Feryal
We analyze archival Chandra and XMM-Newton data of 4U 0142+61 within the context of the surface thermal emission and magnetospheric scattering model. We show that the 4U 0142+61 spectrum can be fit very well with this physical model that contains only four parameters. The system parameters can be tightly constrained from the fits, yielding a surfa…
Analysis of the Sensitivity of Solar Rotation to Helioseismic Data from GONG, GOLF, and MDI Observations
Eff-Darwich, A.; Korzennik, S. G.; Jiménez-Reyes, S. J. +1 more
Accurate determination of the rotation rate in the radiative zone of the Sun from helioseismic observations requires rotational frequency splittings of exceptional quality as well as reliable inversion techniques. Here we present inferences based on mode parameters calculated from 2088 day MDI, GONG, and GOLF time series that were fitted to estima…
Coronal Hard X-Ray Emission Associated with Radio Type III Bursts
Krucker, Säm; Bale, S. D.; Lin, R. P. +4 more
We report on a purely coronal hard X-ray source detected in a partially disk-occulted solar flare by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) that is associated with radio type III bursts and a suprathermal electron event detected near 1 AU by the WIND 3-D Plasma and Energetic Particle (3DP) instrument. Several observation…
New Young Brown Dwarfs in the Orion Molecular Cloud 2/3 Region
Luhman, K. L.; Smith, J. D.; Megeath, S. T. +7 more
Forty new low-mass members with spectral types ranging from M4 to M9 have been confirmed in the Orion Molecular Cloud (OMC) 2/3 region. Through deep, I-, z'-, J-, H-, and K-band photometry of a 20' × 20' field in OMC 2/3, we selected brown dwarf candidates for follow-up spectroscopy. Low-resolution far-red and near-infrared spectra were obtained f…
The Globular Cluster System of M60 (NGC 4649). I. Canada-France-Hawaii Telescope MOS Spectroscopy and Database
Rey, Soo-Chang; Lee, Myung Gyoon; Hwang, Ho Seong +7 more
We present radial velocity measurements for globular clusters in M60, a giant elliptical galaxy in the Virgo Cluster. Target globular cluster candidates were selected using Washington photometry based on deep 16' × 16' images taken at the KPNO 4 m telescope and using VI photometry derived from Hubble Space Telescope WFPC2 arc…