Search Publications
CLUES about M33: the reversed radial stellar age gradient in the outskirts of Triangulum galaxy
Minchev, Ivan; Libeskind, Noam I.; Knebe, Alexander +3 more
HST/ACS observations along the major axis of M33 show that the mean age of its stars decreases with increasing distance from the galaxy centre. Such a behaviour is consistent with an inside-out growth of the disc. However, in the outermost observed field, at r ≃ 11.6 kpc, a reversal of this gradient is detected, with old stars found in high percen…
Spatially associated clump populations in Rosette from CO and dust maps
Klessen, Ralf S.; Ossenkopf-Okada, Volker; Schneider, Nicola +3 more
Spatial association of clumps from different tracers turns out to be a valuable tool to determine the physical properties of molecular clouds. It provides a reliable estimate for the X-factors, serves to trace the density of clumps seen in column densities only, and allows one to measure the velocity dispersion of clumps identified in dust emissio…
Protostellar classification using supervised machine learning algorithms
Miettinen, O.
Classification of young stellar objects (YSOs) into different evolutionary stages helps us to understand the formation process of new stars and planetary systems. Such classification has traditionally been based on spectral energy distribution (SED) analysis. An alternative approach is provided by supervised machine learning algorithms, which can …
Observational study on the fine structure and dynamics of a solar jet. II. Energy release process revealed by spectral analysis
Shibata, Kazunari; Ichimoto, Kiyoshi; Ueno, Satoru +3 more
We report on a solar jet phenomenon associated with the C5.4 class flare on 2014 November 11. The data of the jet was provided by the Solar Dynamics Observatory, the X-Ray Telescope (XRT) aboard Hinode, and the Interface Region Imaging Spectrograph and Domeless Solar Telescope (DST) at Hida Observatory, Kyoto University. These plentiful data enabl…
Astro-H/Hitomi data analysis, processing, and archive
Miller, Eric D.; Yaqoob, Tahir; Terada, Yukikatsu +14 more
Astro-H is the x-ray/gamma-ray mission led by Japan with international participation, launched on February 17, 2016. Soon after launch, Astro-H was renamed Hitomi. The payload consists of four different instruments (SXS, SXI, HXI, and SGD) that operate simultaneously to cover the energy range from 0.3 keV up to 600 keV. On March 27, 2016, JAXA los…
Planetary nebulae with UVIT: Far ultra-violet halo around the Bow Tie nebula (NGC 40)
Sutaria, F.; Murthy, J.; Ray, A. +3 more
Context. NGC 40 is a planetary nebula with diffuse X-ray emission, suggesting an interaction of the high-speed wind from WC8 central star (CS) with the nebula. It shows strong C IV 1550 Å emission that cannot be explained by thermal processes alone. We present here the first map of this nebula in C IV emission using broad band filters on the Ultra…
Space-based Coronagraphic Imaging Polarimetry of the TW Hydrae Disk: Shedding New Light on Self-shadowing Effects
Debes, John H.; Schneider, Glenn; Chen, Christine H. +6 more
We present Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer coronagraphic imaging polarimetry of the TW Hydrae protoplanetary disk. These observations simultaneously measure the total and polarized intensity, allowing direct measurement of the polarization fraction across the disk. In accord with the self-shadowing hypothe…
Line shapes of the magnesium resonance lines in cool DZ white dwarf atmospheres
Dufour, P.; Kielkopf, J. F.; Allard, N. F. +4 more
Context. Line shapes of the magnesium resonance lines in white dwarf spectra are determined by the properties of magnesium atoms and the structure of the white dwarf atmosphere. Through their blanketing effect, these lines have a dominant influence on the model structure and thus on the determination from the spectra of other physical parameters t…
Improved mass constraints for two nearby strong-lensing elliptical galaxies from Hubble Space Telescope imaging
Lucey, John R.; Smith, Russell J.; Collier, William P.
We analyse newly obtained Hubble Space Telescope imaging for two nearby strong lensing elliptical galaxies, SNL-1 (z = 0.03) and SNL-2 (z = 0.05), in order to improve the lensing mass constraints. The imaging reveals previously unseen structure in both the lens galaxies and lensed images. For SNL-1, which has a well resolved source, we break the m…
A matched filter approach for blind joint detection of galaxy clusters in X-ray and SZ surveys
Arnaud, M.; Melin, J. -B.; Tarrío, P.
The combination of X-ray and Sunyaev-Zeldovich (SZ) observations can potentially improve the cluster detection efficiency, when compared to using only one of these probes, since both probe the same medium, the hot ionized gas of the intra-cluster medium. We present a method based on matched multifrequency filters (MMF) for detecting galaxy cluster…