Search Publications
Solar Flare Prediction Using Advanced Feature Extraction, Machine Learning, and Feature Selection
Gallagher, Peter T.; Bloomfield, D. Shaun; Colak, Tufan +3 more
Novel machine-learning and feature-selection algorithms have been developed to study: i) the flare-prediction-capability of magnetic feature (MF) properties generated by the recently developed Solar Monitor Active Region Tracker (SMART); ii) SMART's MF properties that are most significantly related to flare occurrence. Spatiotemporal association a…
LoCuSS: The Steady Decline and Slow Quenching of Star Formation in Cluster Galaxies over the Last Four Billion Years
Finoguenov, A.; Smith, G. P.; Okabe, N. +8 more
We present an analysis of the levels and evolution of star formation activity in a representative sample of 30 massive galaxy clusters at 0.15 < z < 0.30 from the Local Cluster Substructure Survey, combining wide-field Spitzer/MIPS 24 µm data with extensive spectroscopy of cluster members. The specific SFRs of massive ( {M} \gtrsim 10^…
Bright radio emission from an ultraluminous stellar-mass microquasar in M 31
Done, Chris; Macquart, Jean-Pierre; Della Valle, Massimo +34 more
A subset of ultraluminous X-ray sources (those with luminosities of less than 1040 erg s-1 ref. 1) are thought to be powered by the accretion of gas onto black holes with masses of ~5-20, probably by means of an accretion disk. The X-ray and radio emission are coupled in such Galactic sources; the radio emission originates in…
First Spectroscopic Evidence for High Ionization State and Low Oxygen Abundance in Lyα Emitters
Ono, Yoshiaki; Ouchi, Masami; Shimasaku, Kazuhiro +3 more
We present results from Keck/NIRSPEC and Magellan/MMIRS follow-up spectroscopy of Lyα emitters (LAEs) at z = 2.2 identified in our Subaru narrowband survey. We successfully detect Hα emission from seven LAEs, and perform a detailed analysis of six LAEs free from active galactic nucleus activity, two out of which, CDFS-3865 and COSMOS-30679, have […
Low Masses and High Redshifts: The Evolution of the Mass-Metallicity Relation
Martin, Crystal L.; Bunker, Andrew J.; Scarlata, Claudia +15 more
We present the first robust measurement of the high redshift mass-metallicity (MZ) relation at 108 <~ M/M ⊙ <~ 1010, obtained by stacking spectra of 83 emission-line galaxies with secure redshifts between 1.3 <~ z <~ 2.3. For these redshifts, infrared grism spectroscopy with the Hubble Space Telescope W…
Exoplanet Transit Spectroscopy Using WFC3: WASP-12 b, WASP-17 b, and WASP-19 b
Deming, Drake; Madhusudhan, Nikku; Burrows, Adam +3 more
We report an analysis of transit spectroscopy of the extrasolar planets WASP-12 b, WASP-17 b, and WASP-19 b using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We analyze the data for a single transit for each planet using a strategy similar, in certain aspects, to the techniques used by Berta et al., but we extend their meth…
Planck intermediate results. X. Physics of the hot gas in the Coma cluster
Böhringer, H.; Kneissl, R.; Dahle, H. +207 more
We present an analysis of Planck satellite data on the Coma cluster observed via the Sunyaev-Zeldovich effect. Thanks to its great sensitivity, Planck is able, for the first time, to detect SZ emission up to r ≈ 3 × R500. We test previously proposed spherically symmetric models for the pressure distribution in clusters against the azimu…
Calibration of the total infrared luminosity of nearby galaxies from Spitzer and Herschel bands
Helou, G.; Boquien, M.; Roussel, H. +20 more
When combined with infrared observations with the Spitzer telescope (3 to 160 µm), the Herschel Space Observatory now fully samples the thermal dust emission up to 500 µm and enables us to better estimate the total infrared-submm energy budget (LTIR) of nearby galaxies. We present new empirical calibrations to estimate resol…
GOODS-Herschel: radio-excess signature of hidden AGN activity in distant star-forming galaxies
Daddi, E.; Elbaz, D.; Le Floc'h, E. +23 more
Context. A tight correlation exists between far-infrared and radio emission for star-forming galaxies (SFGs), which seems to hold out to high redshifts (z ≈ 2). Any excess of radio emission over that expected from star formation processes is most likely produced by an active galactic nucleus (AGN), often hidden by large amounts of dust and gas. Id…
Limits on anisotropic inflation from the Planck data
Komatsu, Eiichiro; Kim, Jaiseung
Temperature anisotropy of the cosmic microwave background offers a test of the fundamental symmetry of spacetime during cosmic inflation. Violation of rotational symmetry yields a distinct signature in the power spectrum of primordial fluctuations as P(k)=P0(k)[1+g*(k^·E^cl)2], where E^cl is a…