Search Publications
Missions
Journals
Publication Years
An X-Ray Flare from 47 Cas
Karmakar, Subhajeet; Pandey, Jeewan C.
Using XMM-Newton observations, we investigate properties of a flare from the very active but poorly known stellar system 47 Cas. The luminosity at the peak of the flare is found to be 3.54 × 1030 erg {{s}-1}, which is ∼2 times higher than that at a quiescent state. The quiescent state corona of 47 Cas can be represented by tw…
A Search for Population III Galaxies in CLASH. I. Singly-imaged Candidates at High Redshift
Östlin, Göran; Melinder, Jens; Zitrin, Adi +6 more
Population III (Pop III) galaxies are predicted to exist at high redshifts and may be rendered sufficiently bright for detection with current telescopes when gravitationally lensed by a foreground galaxy cluster. Pop III galaxies that exhibit strong Lyα emission should furthermore be identifiable from broadband photometry because of their unusual …
Broadband X-Ray Spectral Investigations of Magnetars, 4U 0142+61, 1E 1841-045,1E 2259+586, AND 1E 1048.1-5937
Göğüş, Ersin; Weng, Shan-Shan
We have generated an extended version of a rather simplified but physically oriented three-dimensional magnetar emission model, STEMS3D, to allow spectral investigations up to 100 keV. We then applied our model to the broadband spectra of four magnetars: 4U 0142+61, 1E 1841-045, 1E 2259+586, and 1E 1048.1-5937, using data collected with Swift/XRT …
Exploration of quasars with the Gaia mission
Wambsganss, Joachim; Proft, Svea
We analyze the opportunities in and limits to investigating quasars with the Gaia satellite by studying Gaia's low- and high-resolution quasar spectra, with consideration of their signal-to-noise ratios. Furthermore, we explore bright quasars from the Sloan Digital Sky Survey with broad emission lines (BELs) redshifted into the spectral range of G…
Dynamic SEP event probability forecasts
Kahler, S. W.; Ling, A.
The forecasting of solar energetic particle (SEP) event probabilities at Earth has been based primarily on the estimates of magnetic free energy in active regions and on the observations of peak fluxes and fluences of large (≥ M2) solar X-ray flares. These forecasts are typically issued for the next 24 h or with no definite expiration time, which …
Magnesium-rich Ejecta in the SNR G284.3-1.8 Around the High-mass Gamma-Ray Binary 1FGL J1018.6-5856
Pavlov, George G.; Kargaltsev, Oleg; Rangelov, Blagoy +1 more
We present results from two Chandra observations of the 16.6 day X-ray/γ-ray high-mass binary 1FGL J1018.6-5856 located at the center of the supernova remnant (SNR) G284.3-1.8. The binary spectra, separated by 0.25 in binary phase, are fit with an absorbed power-law model with {{Γ }}≈ 1.7-1.8 for both observations (the flux during the second obser…
Herschel-PACS observations of discs in the η Chamaeleontis association
Dent, W. R. F.; Kamp, I.; Montesinos, B. +6 more
Context. Protoplanetary discs are the birthplace of planets. Studying protoplanetary discs is the key to constraining theories of planet formation. By observing dust and gas in associations at different ages we can study the evolution of these discs, their clearing timescales, and their physical and geometrical properties.The stellar association η…
Two Populations of Old Star Clusters in the Spiral Galaxy M101 Based on HST/ACS Observations
Whitmore, Bradley C.; Chandar, Rupali; Simanton, Lesley A.
We present a new photometric catalog of 326 candidate globular clusters (GCs) in the nearby spiral galaxy M101, selected from B, V, and I Hubble Space Telescope Advanced Camera for Surveys images. The luminosity function (LF) of these clusters has an unusually large number of faint sources compared with GCLFs in many other spiral galaxies. Accordi…
Total mass of six quiescent prominences estimated from their multi-spectral observations
Heinzel, P.; Golub, L.; Schwartz, P. +4 more
Context. Total masses of six solar prominences were estimated using prominence multi-spectral observations (in EUV, X-rays, Hα, and Ca ii H). The observations were made during the observing campaign from April through June 2011.
Aims: The aim of the work was to apply a complex method for the prominence mass estimations that can be used later …
The Atacama Cosmology Telescope: The LABOCA/ACT Survey of Clusters at All Redshifts
Hilton, Matt; Sifón, Cristóbal; Bond, J. Richard +24 more
We present a multi-wavelength analysis of 11 Sunyaev-Zel’dovich effect (SZE)-selected galaxy clusters (10 with new data) from the Atacama Cosmology Telescope (ACT) southern survey. We have obtained new imaging from the Large APEX Bolometer Camera (345 GHz; LABOCA) on the Atacama Pathfinder EXperiment (APEX) telescope, the Australia Telescope Compa…