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Related papers: 174P/Echeclus and its Blue Coma Observed Post-outb…

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The location of surface brightness maxima (e.g. apocentre and pericentre glow) in eccentric debris discs are often used to infer the underlying orbits of the dust and planetesimals that comprise the disc. However, there is a misconception…

Earth and Planetary Astrophysics · Physics 2021-12-07 Elliot M. Lynch , Joshua B. Lovell

(abridged) [...] Methods: In a continued study of the molecular core population of the Pipe Nebula, we present a molecular-line survey of 52 cores. Previous research has shown a variety of different chemical evolutionary stages among the…

Solar and Stellar Astrophysics · Physics 2014-09-05 Jan Forbrich , Karin Öberg , Charles J. Lada , Marco Lombardi , Alvaro Hacar , João Alves , Jill M. Rathborne

Thanks to Rosetta orbiter's and Philae lander's data our knowledge of cometary nuclei composition has experienced a great advancement. The properties of 67P/CG nucleus are discussed and compared with other comets explored in the past by…

Earth and Planetary Astrophysics · Physics 2022-10-07 Gianrico Filacchione , Mauro Ciarniello , Sonia Fornasier , Andrea Raponi

In this work we aim to characterise the dust motion in the inner coma of comet 67P/Churyumov- Gerasimenko to provide constraints for theoretical 3D coma models. The OSIRIS camera onboard the Rosetta mission was able for the first time to…

It has been suggested that multiple scattering on circumstellar dust could explain the non-standard reddening observed in the line-of-sight to Type Ia supernovae. In this work we use Monte Carlo simulations to examine how the scattered…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Rahman Amanullah , Ariel Goobar

(2060) Chiron is a large centaur that has been reported active on multiple occasions including during aphelion passage. Studies of Chirons coma during active periods have resulted in the detection of C(triple)N and CO outgassing.…

Quasars are thought to be powered by supermassive black holes accreting surrounding gas. Central to this picture is a putative accretion disk which is believed to be the source of the majority of the radiative output. It is well known,…

Dust grains of crystalline silicate, which are rarely presented in interstellar space, were found in cometary nuclei. These crystalline silicates are thought to have formed by annealing of amorphous silicate grains or direct condensation of…

Earth and Planetary Astrophysics · Physics 2018-11-07 Yoshiharu Shinnaka , Takafumi Ootsubo , Hideyo Kawakita , Mitsuru Yamaguchi , Mitsuhiko Honda , Jun-ichi Watanabe

Comets are made of volatile and refractory material and naturally experience various degrees of sublimation as they orbit around the Sun. This gas release, accompanied by dust, represents what is traditionally described as activity.…

Earth and Planetary Astrophysics · Physics 2019-05-15 Jean-Baptiste Vincent , Tony Farnham , Ekkehard Kührt , Yuri Skorov , Raphael Marschall , Nilda Oklay , Ramy El-Maarry , Horst Uwe Keller

HR4796A is surrounded by a debris disc, observed in scattered light as an inclined ring. Past observations raised several questions. First, a strong brightness asymmetry detected in polarized reflected light recently challenged our…

The present paper reports on the RXTE observations of the binary X-ray pulsar 4U0115+63, covering an outburst in 1999 March-April with 44 pointings. The 3-30 keV PCA spectra and the 15-50 keV HEXTE spectra were analyzed jointly for the…

Astrophysics · Physics 2008-11-26 Motoki Nakajima , Tatehiro Mihara , Kazuo Makishima , Hisako Niko

We present infrared images and spectra of comets 2P/Encke, 67P/Churyumov-Gerasimenko, and C/2001 HT50 (LINEAR-NEAT) as part of a larger program to observe comets inside of 5 AU from the sun with the Spitzer Space Telescope. The nucleus of…

Mid-infrared spectra from the Medium Resolution Spectrometer on the James Webb Space Telescope have revealed the molecular chemistry of carbon stars in the Large Magellanic Cloud with better resolution and sensitivity than previously…

We extend an existing thermophysical activity model of comet 67P/Churyumov-Gerasimenko to include pressure buildup inside the pebbles making up the nucleus. We test various quantities of H$_{2}$O and CO$_{2}$, in order to simulate the…

Earth and Planetary Astrophysics · Physics 2024-10-07 Nicholas Attree , Christian Schuckart , Dorothea Bischoff , Bastian Gundlach , Jürgen Blum

Infrared observations of the coma of 67P/Churyumov-Gerasimenko were carried out from July to September 2015, i.e., around perihelion (13 August 2015), with the high-resolution channel of the VIRTIS instrument onboard Rosetta. We present the…

We present Hubble ACS images of thirteen dust reddened Type-1 quasars selected from the FIRST/2MASS Red Quasar Survey. These quasars have high intrinsic luminosities after correction for dust obscuration (-23.5 > M_B > -26.2 from…

Astrophysics · Physics 2009-11-13 Tanya Urrutia , Mark Lacy , Robert H. Becker

The Flat Spectrum Radio Quasar PMN J2345-1555 is a bright gamma-ray source, that recently underwent a flaring episode in the IR, UV and gamma-ray bands. The flux changed quasi simultaneously at different frequencies, suggesting that it was…

High Energy Astrophysical Phenomena · Physics 2015-06-15 G. Ghisellini , F. Tavecchio , L. Foschini , G. Bonnoli , G. Tagliaferri

We report the detection of water vapor associated with main-belt comet 358P/PANSTARRS on UT 2024 January 8-9 using the NIRSPEC instrument aboard JWST. We derive a water production rate of Q(H2O)=(5.0+/-0.2)x10^25 molecules/s, marking only…

We discuss dust properties in the interstellar medium (ISM) of nearby normal galaxies, by comparing observations in the ultraviolet (UV) with simulations by a radiative transfer model. The observed UV colours of nearby galaxies show a…