Search Publications
Solar energetic particle events during the rise phases of solar cycles 23 and 24
Srivastava, A. K.; Chandra, R.; Gopalswamy, N. +13 more
We present a comparative study of the properties of coronal mass ejections (CMEs) and flares associated with the solar energetic particle (SEP) events in the rising phases of solar cycles (SC) 23 (1996-1998) (22 events) and 24 (2009-2011) (20 events), which are associated with type II radio bursts. Based on the SEP intensity, we divided the events…
Constraining Stellar Feedback: Shock-ionized Gas in Nearby Starburst Galaxies
Martin, Crystal L.; Conselice, Christopher J.; Calzetti, Daniela +3 more
We investigate the properties of feedback-driven shocks in eight nearby starburst galaxies using narrow-band imaging data from the Hubble Space Telescope. We identify the shock-ionized component via the line diagnostic diagram [O III] (λ5007)/Hβ versus [S II] (λλ6716, 6731) (or [N II] (λ6583))/Hα, applied to resolved regions 3-15 pc in size. We di…
A z = 3.045 Lyα emitting halo hosting a QSO and a possible candidate for AGN-triggered star formation.
Carswell, R. F.; Rauch, M.; Becker, G. D. +2 more
In this third paper in a series on the nature of extended, asymmetric Lyα emitters at z ∼ 3 we report the discovery, in an ultra-deep, blind, spectroscopic long-slit survey, of a Lyα emitting halo around a QSO at redshift 3.045. The QSO is a previously known, obscured active galactic nucleus (AGN). The Lyα emitting halo appears extended along the …
Astrometric reduction of Cassini ISS images of the Saturnian satellites Mimas and Enceladus
Charnoz, S.; Cooper, N. J.; Lainey, V. +2 more
Aims: We provide astrometric observations of two of Saturn's main satellites, Mimas and Enceladus, using high resolution Cassini ISS Narrow Angle Camera images.
Methods: We developed a simplified astrometric reduction model for Cassini ISS images as an alternative to the one proposed by the Jet Propulsion Labratory (JPL). The particular …
Cr-K Emission Line as a Constraint on the Progenitor Properties of Supernova Remnants
Li, Aigen; Tsunemi, H.; Lu, F. J. +4 more
We perform a survey of the Cr, Mn, and Fe-K emission lines in young supernova remnants (SNRs) with the Japanese X-ray astronomy satellite Suzaku. The Cr and/or Mn emission lines are detected in 3C 397 and 0519-69.0 for the first time. We also confirm the detection of these lines in Kepler, W49B, N103B, and Cas A. We derive the line parameters (i.e…
A Bayesian Method for the Analysis of the Dust Emission in the Far-infrared and Submillimeter
Paladini, R.; Piacentini, F.; Noriega-Crespo, A. +3 more
We present a method, based on Bayesian statistics, to fit the dust emission parameters in the far-infrared and submillimeter wavelengths. The method estimates the dust temperature and spectral emissivity index, plus their relationship, properly taking into account the statistical and systematic uncertainties. We test it on three sets of simulated …
Response of Uranus' auroras to solar wind compressions at equinox
Cowley, S. W. H.
We consider open flux production and magnetic tail formation for the unique physical circumstances at Uranus, where the planet's spin axis lies close to the orbit plane, while the magnetic dipole has a large ~60° inclination to the spin axis. Under these circumstances, open flux production and transport into the nightside can in principle occur co…
Scaling relationships and concavity of small valley networks on Mars
Fassett, Caleb I.; Penido, Julita C.; Som, Sanjoy M.
Valley networks are widely interpreted as the preserved erosional record of water flowing across the martian surface. The manner in which valley morphometric properties scale with drainage area has been widely examined on Earth. Earlier studies assessing these properties on Mars have suggested that martian valleys are morphometrically distinct fro…
A H I Imaging Survey of Asymptotic Giant Branch Stars
Le Bertre, T.; Matthews, L. D.; Johnson, M. C. +1 more
We present an imaging study of a sample of eight asymptotic giant branch stars in the H I 21 cm line. Using observations from the Very Large Array, we have unambiguously detected H I emission associated with the extended circumstellar envelopes of six of the targets. The detected H I masses range from M H I ≈ 0.015-0.055 M solar
Dual Halos and Formation of Early-type Galaxies
Lee, Myung Gyoon; Park, Hong Soo
We present a determination of the two-dimensional shape parameters of the blue and red globular cluster systems (GCSs) in a large number of elliptical galaxies and lenticular galaxies (early-type galaxies, called ETGs). We use a homogeneous data set of the globular clusters in 23 ETGs obtained from the HST/ACS Virgo Cluster Survey. The position an…