Search Publications
Linearized iterative least-squares (LIL): a parameter-fitting algorithm for component separation in multifrequency cosmic microwave background experiments such as Planck
Khatri, Rishi
We present an efficient algorithm for least-squares parameter fitting, optimized for component separation in multifrequency cosmic microwave background (CMB) experiments. We sidestep some of the problems associated with non-linear optimization by taking advantage of the quasi-linear nature of the foreground model. We demonstrate our algorithm, lin…
Error analysis for retrieval of Venus' IR surface emissivity from VIRTIS/VEX measurements
Haus, Rainer; Kappel, David; Arnold, Gabriele
Venus' surface emissivity data in the infrared can serve to explore the planet's geology. The only global data with high spectral, spatial, and temporal resolution and coverage at present is supplied by nightside emission measurements acquired by the Visible and InfraRed Thermal Imaging Spectrometer VIRTIS-M-IR (1.0 - 5.1 µm) aboard ESA's Ve…
Host Galaxy Properties and Black Hole Mass of Swift J164449.3+573451 from Multi-wavelength Long-term Monitoring and HST Data
Urata, Yuji; Sakamoto, Takanori; Im, Myungshin +6 more
We study the host galaxy properties of the tidal disruption object Swift J164449.3+573451 using long-term optical to near-infrared (NIR) data. First, we decompose the galaxy surface brightness distribution and analyze the morphology of the host galaxy using high-resolution Hubble Space Telescope WFC3 images. We conclude that the host galaxy is bul…
Physical properties of the extreme Centaur and super-comet candidate 2013 AZ60
Pál, A.; Szabó, Gy. M.; Acosta-Pulido, J. +12 more
We present estimates of the basic physical properties including size and albedo of the extreme Centaur 2013 AZ60. These properties have been derived from optical and thermal infrared measurements. Our optical measurements revealed a probable full period of ≈9.4 h with a shallow amplitude of 4.5%. By combining optical brightness informat…
XMM-Newton observation of SNR J0533-7202 in the Large Magellanic Cloud
Haberl, F.; Filipović, M. D.; Maggi, P. +5 more
Aims: We present an X-ray study of the supernova remnant SNR J0533-7202 in the Large Magellanic Cloud (LMC) and determine its physical characteristics based on its X-ray emission.
Methods: We observed SNR J0533-7202 with XMM-Newton (background flare-filtered exposure times of 18 ks EPIC-pn and 31 ks EPIC-MOS1, EPIC-MOS2). We produced X-r…
An empirical approach to modeling ion production rates in Titan's ionosphere II: Ion production rates on the nightside
Coates, A. J.; Rymer, A.; Wellbrock, A. +9 more
Ionization of neutrals by precipitating electrons and ions is the main source of Titan's nightside ionosphere. This paper has two goals: (1) characterization of the role of electron impact ionization on the nightside ionosphere for different magnetospheric conditions and (2) presentation of empirical ion production rates determined using densities…
RATAN-600 Observations of Small-Scale Structures with High Spectral Resolution
Alissandrakis, C. E.; Bogod, V. M.; Kaltman, T. I. +1 more
We present observations of quiet-Sun small-scale structures (SSS) in the microwave range with the Radio Astronomical Telescope of the Academy of Sciences 600 (RATAN-600) spectral-polarization facility in a wide range of frequencies. The SSS are regularly recorded in routine observations of the large reflector-type radio telescope and represent man…
X-ray measurement of electron and magnetic-field energy densities in the west lobe of the giant radio galaxy 3C 236
Isobe, Naoki; Koyama, Shoko
X-ray emission associated with the west lobe of the giant radio galaxy 3C 236 was investigated with the Suzaku observatory to evaluate the energetics in the lobe. After removing contamination from point-like X-ray sources detected with Chandra and subtracting the X-ray and non-X-ray backgrounds, the Suzaku spectrum from the lobe was reproduced by …
X-ray spectral parameters for a sample of 95 active galactic nuclei
Vasylenko, A. A.; Fedorova, E. V.; Zhdanov, V. I.
We present a broadband X-ray analysis of a new homogeneous sample of 95 active galactic nuclei (AGN) from the 22-month Swift/BAT all-sky survey. For this sample we treated jointly the X-ray spectra observed by XMM-Newton and INTEGRAL missions for the total spectral range of 0.5–250 keV. Photon index
The Transitional Disk around IRAS 04125+2902
Andrews, S.; Wilner, D.; Espaillat, C. +4 more
Resolved submillimeter imaging of transitional disks is increasingly revealing the complexity of disk structure. Here, we present the first high-resolution submillimeter image of a recently identified transitional disk around IRAS 04125+2902 in the Taurus star-forming region. We measure an inner disk hole of ∼20 AU around IRAS 04125+2902 by simult…