Search Publications
Temperatures of dust and gas in S 140
Ossenkopf, V.; van der Tak, F. F. S.; Kramer, C. +4 more
Context. In dense parts of interstellar clouds (≥105 cm-3), dust and gas are expected to be in thermal equilibrium, being coupled via collisions. However, previous studies have shown that in the presence of intense radiation fields, the temperatures of the dust and gas may remain decoupled even at higher densities.
Aims:…
First extreme and far ultraviolet spectrum of a Comet Nucleus: Results from 67P/Churyumov-Gerasimenko
Stern, S. A.; Feldman, P. D.; Bertaux, J. -L. +7 more
We used the Alice spectrograph onboard the Rosetta comet orbiter spacecraft to observe the surface of Comet 67P/Churyumov-Gerasimenko in the extreme and far ultraviolet (EUV/FUV) from 700 to 2050 Å in mid-August 2014. These observations were before significant EUV/FUV coma signatures were observed by Alice. The resulting coadded spectrum has high …
Uncovering the Nucleus Candidate for NGC 253
Schirmer, M.; Díaz, R. J.; Günthardt, G. I. +4 more
NGC 253 is the nearest spiral galaxy with a nuclear starburst that becomes the best candidate for studying the relationship between starburst and active galactic nucleus activity. However, this central region is veiled by large amounts of dust, and it has been so far unclear which is the true dynamical nucleus to the point that there is no strong …
Dynamics of Microwave Sources Associated with the Neutral Line and the Magnetic-Field Parameters of Sunspots as a Factor in Predicting Large Flares
Abramov-Maximov, V. E.; Borovik, V. N.; Opeikina, L. V. +1 more
We studied the evolution of five active regions (ARs) where strong X-class flares occurred in 2011 - 2012 (NOAA ARs 11158, 11166, 11263, 11283 and 11520). Our study focuses on the pre-flare phase of these ARs (during a few days before the flare) to reveal features in the microwave radiation and magnetic-field characteristics of the ARs that indica…
The Origin of the Hot Gas in the Galactic Halo: Testing Galactic Fountain Models' X-Ray Emission
Henley, David B.; Shelton, Robin L.; Hill, Alex S. +2 more
We test the X-ray emission predictions of galactic fountain models against XMM-Newton measurements of the emission from the Milky Way's hot halo. These measurements are from 110 sight lines, spanning the full range of Galactic longitudes. We find that a magnetohydrodynamical simulation of a supernova-driven interstellar medium, which features a fl…
Cross-correlation of Near- and Far-infrared Background Anisotropies as Traced by Spitzer and Herschel
Gong, Yan; Cooray, Asantha; Mitchell-Wynne, Ketron +3 more
We present the cross-correlation between the far-infrared (far-IR) background fluctuations as measured with the Herschel Space Observatory at 250, 350, and 500 µm and the near-infrared (near-IR) background fluctuations with the Spitzer Space Telescope at 3.6 and 4.5 µm. The cross-correlation between the FIR and NIR background anisotrop…
Transpolar arc observation after solar wind entry into the high-latitude magnetosphere
Wei, Y.; Zong, Q. -G.; Fear, R. C. +11 more
Recently, Cluster observations have revealed the presence of new regions of solar wind plasma entry at the high-latitude magnetospheric lobes tailward of the cusp region, mostly during periods of northward interplanetary magnetic field. In this study, observations from the Global Ultraviolet Imager (GUVI) experiment on board the TIMED spacecraft a…
A method of complex background estimation in astronomical images
Popowicz, A.; Smolka, B.
In this paper, we present a novel approach to the estimation of strongly varying backgrounds in astronomical images by means of small-objects removal and subsequent missing pixels interpolation. The method is based on the analysis of a pixel local neighbourhood and utilizes the morphological distance transform. In contrast to popular background-es…
Evidence for Decay of Turbulence by MHD Shocks in the ISM via CO Emission
Larson, Rebecca L.; Green, Joel D.; Yang, Yao-Lun +1 more
We utilize observations of sub-millimeter rotational transitions of CO from a Herschel Cycle 2 open time program (“COPS”, PI: J. Green) to identify previously predicted turbulent dissipation by magnetohydrodynamic (MHD) shocks in molecular clouds. We find evidence of the shocks expected for dissipation of MHD turbulence in material not associated …
The Herschel Virgo Cluster Survey. XVII. SPIRE point-source catalogs and number counts
Zibetti, Stefano; Bizzocchi, Luca; De Looze, Ilse +19 more
Aims: We present three independent catalogs of point-sources extracted from SPIRE images at 250, 350, and 500 µm, acquired with the Herschel Space Observatory as a part of the Herschel Virgo Cluster Survey (HeViCS). The catalogs have been cross-correlated to consistently extract the photometry at SPIRE wavelengths for each object.
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