Search Publications

Thermally anomalous features in the subsurface of Enceladus's south polar terrain
DOI: 10.1038/s41550-017-0063 Bibcode: 2017NatAs...1E..63L

Sotin, C.; Lorenz, R. D.; West, R. D. +15 more

Saturn's moon Enceladus is an active world. In 2005, the Cassini spacecraft witnessed for the first time water-rich jets venting from four anomalously warm fractures (called sulci) near its south pole1,2. Since then, several observations have provided evidence that the source of the material ejected from Enceladus is a large underground…

2017 Nature Astronomy
Cassini 36
Star Formation at z = 2.481 in the Lensed Galaxy SDSS J1110+6459. II. What is Missed at the Normal Resolution of the Hubble Space Telescope?
DOI: 10.3847/1538-4357/aa775e Bibcode: 2017ApJ...843...79R

Rigby, J. R.; Sharon, K.; Gladders, M. D. +6 more

For lensed galaxy SGAS J111020.0+645950.8 at redshift z = 2.481, which is magnified by a factor of 28 ± 8, we analyze the morphology of star formation, as traced by rest-frame ultraviolet emission, in both the highly magnified source plane and simulations of how this galaxy would appear without lensing magnification. Were this galaxy not lensed, b…

2017 The Astrophysical Journal
eHST 35
Milky Way Tomography with K and M Dwarf Stars: The Vertical Structure of the Galactic Disk
DOI: 10.3847/1538-4357/aa77fd Bibcode: 2017ApJ...843..141F

Yanny, Brian; Ferguson, Deborah; Gardner, Susan

We use the number density distributions of K and M dwarf stars with vertical height from the Galactic disk, determined using observations from the Sloan Digital Sky Survey, to probe the structure of the Milky Way disk across the survey’s footprint. Using photometric parallax as a distance estimator we analyze a sample of several million disk stars…

2017 The Astrophysical Journal
Gaia 35
A dichotomy between the hard state spectral properties of black hole and neutron star X-ray binaries
DOI: 10.1093/mnras/stw2514 Bibcode: 2017MNRAS.466..194B

Sunyaev, R.; Gilfanov, M.; Burke, M. J.

We analyse the spectra of black hole (BH) and neutron star (NS) X-ray binaries (XBs) in the hard state using archival RXTE observations. We find that there is a clear dichotomy in the strength of Comptonization between NS and BH sources, as measured by both the Compton y-parameter and the amplification factor A, with distinct groups of BH and NS X…

2017 Monthly Notices of the Royal Astronomical Society
XMM-Newton 35
Mapping the hot gas temperature in galaxy clusters using X-ray and Sunyaev-Zel'dovich imaging
DOI: 10.1051/0004-6361/201629810 Bibcode: 2017A&A...606A..64A

Adam, R.; Arnaud, M.; Benoît, A. +42 more

We propose a method to map the temperature distribution of the hot gas in galaxy clusters that uses resolved images of the thermal Sunyaev-Zel'dovich (tSZ) effect in combination with X-ray data. Application to images from the New IRAM KIDs Array (NIKA) and XMM-Newton allows us to measure and determine the spatial distribution of the gas temperatur…

2017 Astronomy and Astrophysics
XMM-Newton 35
Radio jets in NGC 4151: where eMERLIN meets HST
DOI: 10.1093/mnras/stx2205 Bibcode: 2017MNRAS.472.3842W

Muxlow, T. W. B.; Argo, M. K.; Knapen, J. H. +11 more

We present high-sensitivity eMERLIN radio images of the Seyfert galaxy NGC 4151 at 1.51 GHz. We compare the new eMERLIN images to those from archival MERLIN observations in 1993 to determine the change in jet morphology in the 22 yr between observations. We report an increase by almost a factor of 2 in the peak flux density of the central core com…

2017 Monthly Notices of the Royal Astronomical Society
eHST 35
H2 in low-ionization structures of planetary nebulae
DOI: 10.1093/mnras/stw2736 Bibcode: 2017MNRAS.465.1289A

Gonçalves, Denise R.; Akras, Stavros; Ramos-Larios, Gerardo

We report the detection of near-IR H2 emission from the low-ionization structures (knots) in two planetary nebulae. The deepest ever high-angular-resolution H2 (1-0) S(1) at 2.122 µm, H2 (2-1) S(1) at 2.248 µm and Brγ images of K 4-47 and NGC 7662, obtained using the Near InfraRed Imager and Spectromete…

2017 Monthly Notices of the Royal Astronomical Society
eHST 35
Seasonal changes of the volatile density in the coma and on the surface of comet 67P/Churyumov-Gerasimenko
DOI: 10.1093/mnras/stx866 Bibcode: 2017MNRAS.469S..20K

Altwegg, Kathrin; Rubin, Martin; Läuter, Matthias +1 more

Starting from several monthly data sets of Rosetta's COmetary Pressure Sensor, we reconstruct the gas density in the coma around comet 67P/Churyumov-Gerasimenko. The underlying inverse gas model is constructed by fitting ten thousands of measurements to thousands of potential gas sources distributed across the entire nucleus surface. The ensuing s…

2017 Monthly Notices of the Royal Astronomical Society
Rosetta 35
The Formation and Physical Origin of Highly Ionized Cooling Gas
DOI: 10.3847/1538-4357/aa8e9c Bibcode: 2017ApJ...848..122B

Heckman, Timothy M.; Bordoloi, Rongmon; Wagner, Alexander Y. +1 more

We present a simple model that explains the origin of warm, diffuse gas seen primarily as highly ionized absorption-line systems in the spectra of background sources. We predict the observed column densities of several highly ionized transitions such as O VI, O vii, Ne viii, N v, and Mg x, and we present a unified comparison of the model predictio…

2017 The Astrophysical Journal
eHST 35
Gaia Assorted Mass Binaries Long Excluded from SLoWPoKES (GAMBLES): Identifying Ultra-wide Binary Pairs with Components of Diverse Mass
DOI: 10.3847/1538-3881/aa6d55 Bibcode: 2017AJ....153..259O

Stassun, Keivan G.; Oelkers, Ryan J.; Dhital, Saurav

The formation and evolution of binary star systems are some of the remaining key questions in modern astronomy. Wide binary pairs (separations >103 au) are particularly intriguing because their low binding energies make it difficult for the stars to stay gravitationally bound over extended timescales, and thus to probe the dynamics o…

2017 The Astronomical Journal
Gaia 35