Search Publications
X-ray emission from charge exchange in the Cygnus Loop SNR
Wang, Q. Daniel; Roberts, Shawn R.
The Cygnus Loop has been the focus of substantial debate concerning the contribution of charge exchange (CX) to supernova remnant (SNR) X-ray emission. We take advantage of a distinct feature of CX, enhanced Kα forbidden line emission, and employ the energy centroid of the O VII Kα triplet as a diagnostic. Based on X-ray spectra extracted from an …
Constraining the parameters of the pulsar wind nebula DA 495 and its pulsar with Chandra and XMM-Newton
Zyuzin, D.; Danilenko, A.; Shibanov, Yu. +1 more
We present spectral and timing analyses of the X-ray emission from the pulsar wind nebula DA 495 and its central object, J1952.2+2925, suggested to be the pulsar, using archival Chandra and XMM-Newton data. J1952.2+2925 has a pure thermal spectrum which is equally well fitted either by the blackbody model with a temperature of ≈215 eV and an emitt…
The opposition effect in Saturn's main rings as seen by Cassini ISS: 2. Constraints on the ring particles and their regolith with analytical radiative transfer models
Déau, Estelle
The opposition effect in Saturn's main rings is characterized by a surge in ring brightness, when the phase angle approaches zero degree. This effect can be used to derive: physical properties of the ring particles and the ring layer, via the shadow hiding mechanism; and physical properties of the regolith grains that cover the ring particles, via…
Discovery of Collimated Bipolar Outflows in the Planetary Nebula Th 2-A
Danehkar, A.
We present a comprehensive set of spatially resolved, integral field spectroscopic mapping of the Wolf-Rayet planetary nebula Th 2-A, obtained using the Wide Field Spectrograph on the Australian National University 2.3-m telescope. Velocity-resolved Hα channel maps with a resolution of 20 km s-1 allow us to identify different kinematic …
The quasi-periodic behavior of recurrent jets caused by emerging magnetic flux
Yang, J. Y.; Liang, H. F.; Jiang, Y. C. +2 more
A series of recurring jets occurred at the edge of an active region NOAA 11459 on 2012 April 20, and they were observed simultaneously at EUV and soft X-ray wavelengths. They also were sometimes associated with a hard X-ray source at the base region. The jets might have resulted from magnetic reconnection between the newly emerging flux and the pr…
Infrared Two-Color Diagrams for AGB Stars, Post-AGB Stars, and Planetary Nebulae
Suh, Kyung-Won
We present various infrared two-color diagrams (2CDs) for asymptotic giant branch (AGB) stars, post-AGB stars, and Planetary Nebulae (PNe) and investigate possible evolutionary tracks. We use catalogs from the available literature for the sample of 4903 AGB stars (3373 O-rich; 1168 C-rich; 362 S-type), 660 post-AGB stars (326 post-AGB; 334 pre-PN)…
GOODS-Herschel: identification of the individual galaxies responsible for the 80-290 µm cosmic infrared background
Magnelli, B.; Elbaz, D.; Popesso, P. +14 more
Aims: We propose a new method of pushing Herschel to its faintest detection limits using universal trends in the redshift evolution of the far infrared over 24 µm colours in the well-sampled GOODS-North field. An extension to other fields with less multi-wavelength information is presented. This method is applied here to raise the contr…
An X-Ray Flare from 47 Cas
Karmakar, Subhajeet; Pandey, Jeewan C.
Using XMM-Newton observations, we investigate properties of a flare from the very active but poorly known stellar system 47 Cas. The luminosity at the peak of the flare is found to be 3.54 × 1030 erg {{s}-1}, which is ∼2 times higher than that at a quiescent state. The quiescent state corona of 47 Cas can be represented by tw…
A Search for Population III Galaxies in CLASH. I. Singly-imaged Candidates at High Redshift
Östlin, Göran; Melinder, Jens; Zitrin, Adi +6 more
Population III (Pop III) galaxies are predicted to exist at high redshifts and may be rendered sufficiently bright for detection with current telescopes when gravitationally lensed by a foreground galaxy cluster. Pop III galaxies that exhibit strong Lyα emission should furthermore be identifiable from broadband photometry because of their unusual …
Broadband X-Ray Spectral Investigations of Magnetars, 4U 0142+61, 1E 1841-045,1E 2259+586, AND 1E 1048.1-5937
Göğüş, Ersin; Weng, Shan-Shan
We have generated an extended version of a rather simplified but physically oriented three-dimensional magnetar emission model, STEMS3D, to allow spectral investigations up to 100 keV. We then applied our model to the broadband spectra of four magnetars: 4U 0142+61, 1E 1841-045, 1E 2259+586, and 1E 1048.1-5937, using data collected with Swift/XRT …