Search Publications
Discovery of VHE emission towards the Carina arm region with the H.E.S.S. telescope array: HESS J1018-589
Klochkov, D.; Santangelo, A.; Quirrenbach, A. +191 more
The Carina arm region, containing the supernova remnant SNR G284.3-1.8, the high-energy (HE; E > 100 MeV) binary 1FGL J1018.6-5856 and the energetic pulsar PSR J1016-5857 and its nebula, has been observed with the H.E.S.S. telescope array. The observational coverage of the region in very-high-energy (VHE; E > 0.1 TeV) γ-rays benefits from de…
Sizing up Partially Depleted Galaxy Cores
Graham, Alister W.; Dullo, Bililign T.
We have modeled the inner surface brightness profiles of 39 alleged "core" galaxies with the core-Sérsic model, and provide new physical parameters for the largest ever sample of "core" galaxies fit with this model. When present, additional nuclear components were simultaneously modeled and the typical root-mean-square scatter of the fits (out to …
The Stellar and Gas Kinematics of the LITTLE THINGS Dwarf Irregular Galaxy NGC 1569
Brinks, Elias; Hunter, Deidre A.; Johnson, Megan +5 more
In order to understand the formation and evolution of Magellanic-type dwarf irregular (dIm) galaxies, one needs to understand their three-dimensional structure. We present measurements of the stellar velocity dispersion in NGC 1569, a nearby post-starburst dIm galaxy. The stellar vertical velocity dispersion, σz, coupled with the maximu…
A unique isolated dwarf spheroidal galaxy at D = 1.9 Mpc
Makarova, Lidia; Guhathakurta, Puragra; Makarov, Dmitry +5 more
We present a photometric and spectroscopic study of the unique isolated nearby dwarf spheroidal (dSph) galaxy KKR 25. The galaxy was resolved into stars with Hubble Space Telescope/Wide Field Planetary Camera 2 including old red giant branch and red clump. We have constructed a model of the resolved stellar populations and measured the star format…
Dust-to-gas Ratio in the Extremely Metal-poor Galaxy I Zw 18
Cannon, John M.; Bolatto, Alberto D.; Leroy, Adam K. +7 more
The blue compact dwarf galaxy I Zw 18 is one of the most metal-poor systems known in the local universe (12+log(O/H) = 7.17). In this work we study I Zw 18 using data from Spitzer, Herschel Space Telescope, and IRAM Plateau de Bure Interferometer. Our data set includes the most sensitive maps of I Zw 18, to date, in both the far-infrared and the C…
Photometric redshifts with the quasi Newton algorithm (MLPQNA) Results in the PHAT1 contest
Brescia, M.; Cavuoti, S.; Mercurio, A. +1 more
Context. Since the advent of modern multiband digital sky surveys, photometric redshifts (photo-z's) have become relevant if not crucial to many fields of observational cosmology, such as the characterization of cosmic structures and the weak and strong lensing.
Aims: We describe an application to an astrophysical context, namely the evaluati…
The Impact of Polarized Extragalactic Radio Sources on the Detection of CMB Anisotropies in Polarization
Tucci, Marco; Toffolatti, Luigi
Recent polarimetric surveys of extragalactic radio sources (ERS) at frequencies \nu>1GHz are reviewed. By exploiting all the most relevant data on the polarized emission of ERS we study the frequency dependence of polarization properties of ERS between 1.4 and 86GHz. For flat-spectrum sources the median (mean) fractional polarization increases …
The Sub-mJy Radio Population of the E-CDFS: Optical and Infrared Counterpart Identification
Brandt, W. N.; Tozzi, P.; Balestra, I. +9 more
We study a sample of 883 sources detected in a deep Very Large Array survey at 1.4 GHz in the Extended Chandra Deep Field South. This paper focuses on the identification of their optical and infrared (IR) counterparts. We use a likelihood-ratio technique that is particularly useful when dealing with deep optical images to minimize the number of sp…
Wave-particle interaction in a plasmaspheric plume observed by a Cluster satellite
Yuan, Zhigang; Zhou, Meng; Deng, Xiaohua +5 more
The wave-particle interaction is a possible candidate for the energy coupling between the ring current and plasmaspheric plumes. In this paper, we present wave and particle observations made by the Cluster C1 satellite in a plasmaspheric plume in the recovery phase of the geomagnetic storm on 18 July 2005. Cluster C1 simultaneously observed Pc1-2 …
Magnetosphere-atmosphere coupling at Saturn: 1 - Response of thermosphere and ionosphere to steady state polar forcing
Galand, M.; Moore, L.; Müller-Wodarg, I. C. F. +2 more
We present comprehensive calculations of the steady state response of Saturn’s coupled thermosphere-ionosphere to forcing by solar radiation, magnetospheric energetic electron precipitation and high latitude electric fields caused by sub-corotation of magnetospheric plasma. Significant additions to the physical processes calculated in our Saturn T…