Search Publications
Dust properties in H II regions in M 33
Boquien, M.; De Looze, I.; Braine, J. +11 more
Context. The infrared emission (IR) of the interstellar dust has been claimed to be a tracer of the star formation rate. However, the conversion of the IR emission into star formation rate can be strongly dependent on the physical properties of the dust, which are affected by the environmental conditions where the dust is embedded.
Aims: We s…
Statistics of energetic electrons in the magnetotail reconnection
Xu, Xiaojun; Huang, Shiyong; Zhou, Meng +5 more
Magnetic reconnection has long been regarded as an important site for producing energetic electrons in solar terrestrial and astrophysical plasmas. The motivation of this paper is to provide the average properties of energetic electrons in reconnection region, which are crucial for understanding electron energization mechanism but are rarely known…
Ortho-to-para ratio of NH2. Herschel-HIFI observations of ortho- and para-NH2 rotational transitions towards W31C, W49N, W51, and G34.3+0.1
Persson, C. M.; Gerin, M.; Herbst, E. +10 more
We have used the Herschel-HIFI instrument to observe the two nuclear spin symmetries of amidogen (NH2) towards the high-mass star-forming regions W31C (G10.6-0.4), W49N (G43.2-0.1), W51 (G49.5-0.4), and G34.3+0.1. The aim is to investigate the ratio of nuclear spin types, the ortho-to-para ratio (OPR) of NH2 in the translucen…
Complex central structures suggest complex evolutionary paths for barred S0 galaxies
Knapen, Johan H.; Dullo, Bililign T.; Martínez-Lombilla, Cristina
We investigate three barred lenticular galaxies (NGC 2681, NGC 3945 and NGC 4371), which were previously reported to have complex central structures but without a detailed structural analysis of these galaxies' high-resolution data. We have therefore performed four- to six-component (pseudo-)bulge/disc/bar/ring/point source) decompositions of the …
New Spectroscopic Technique Based on Coaddition of Surface Brightness Fluctuations: NGC 4449 and its Stellar Tidal Stream
Romanowsky, Aaron J.; Brodie, Jean P.; Arnold, Jacob A. +5 more
We present a new spectroscopic technique based in part on targeting the upward fluctuations of the surface brightness for studying the internal stellar kinematics and metallicities of galaxies of low surface brightness effects both to galaxies and streams beyond the Local Group. The distance to these systems makes them unsuitable for targeting ind…
Venus Cloud Morphology and Motions from Ground-based Images at the Time of the Akatsuki Orbit Insertion
Hueso, R.; Sánchez-Lavega, A.; Rojas, J. F. +7 more
We report Venus image observations around the two maximum elongations of the planet at 2015 June and October. From these images we describe the global atmospheric dynamics and cloud morphology in the planet before the arrival of JAXA’s Akatsuki mission on 2015 December 7. The majority of the images were acquired at ultraviolet wavelengths (380-410…
Characterizing the particle size distribution of Saturn's A ring with Cassini UVIS occultation data
Colwell, Joshua E.; Esposito, Larry W.; Becker, Tracy M. +1 more
Stellar occultation data from Cassini's Ultraviolet Imaging Spectrograph (UVIS) have revealed diffraction spikes near sharp edges in Saturn's rings. The UVIS High Speed Photometer (HSP) observes these spikes as signals at ring edges that surpass measurements of the unocculted stellar signal. In Saturn's A ring, diffracted light can augment the dir…
The Gini Coefficient as a Tool for Image Family Idenitification in Strong Lensing Systems with Multiple Images
Sharon, Keren; Florian, Michael K.; Gladders, Michael D. +1 more
The sample of cosmological strong lensing systems has been steadily growing in recent years and with the advent of the next generation of space-based survey telescopes, the sample will reach into the thousands. The accuracy of strong lens models relies on robust identification of multiple image families of lensed galaxies. For the most massive len…
SILC: a new Planck internal linear combination CMB temperature map using directional wavelets
Leistedt, Boris; Peiris, Hiranya V.; Pontzen, Andrew +2 more
We present new clean maps of the cosmic microwave background (CMB) temperature anisotropies (as measured by Planck) constructed with a novel internal linear combination (ILC) algorithm using directional, scale-discretized wavelets - scale-discretized, directional wavelet ILC or Scale-discretised, directional wavelet Internal Linear Combination (SI…
Model-independent characterisation of strong gravitational lenses
Bartelmann, M.; Wagner, J.
We develop a new approach to extracting model-independent information from observations of strong gravitational lenses. The approach is based on the generic properties of images near the fold and cusp catastrophes in caustics and critical curves. The observables we used are the relative image positions, the magnification ratios and ellipticities o…