Search Publications
Early-type Galaxies with Tidal Debris and Their Scaling Relations in the Spitzer Survey of Stellar Structure in Galaxies (S4G)
Ho, Luis C.; Erroz-Ferrer, Santiago; Schinnerer, Eva +21 more
Tidal debris around galaxies can yield important clues on their evolution. We have identified tidal debris in 11 early-type galaxies (T <= 0) from a sample of 65 early types drawn from the Spitzer Survey of Stellar Structure in Galaxies (S4G). The tidal debris includes features such as shells, ripples, and tidal tails. A variety of t…
Two-plasma Model for Low Charge State Interplanetary Coronal Mass Ejection Observations
Zurbuchen, Thomas H.; Gruesbeck, Jacob R.; Lepri, Susan T.
Recent ACE/SWICS observations have revealed that ~5% of all in situ observed interplanetary coronal mass ejections include time periods with very low charge state ions found to be associated with prominence eruptions. It was also shown that these low charge state ions are often observed concurrently with very high charge state ions. But, the physi…
Quenched Cold Accretion of a Large-scale Metal-poor Filament due to Virial Shocking in the Halo of a Massive z = 0.7 Galaxy
Kacprzak, Glenn G.; Spitler, Lee R.; Steidel, Charles C. +4 more
Using HST/COS/STIS and HIRES/Keck high-resolution spectra, we have studied a remarkable H I absorbing complex at z = 0.672 toward the quasar Q1317+277. The H I absorption has a velocity spread of Δv = 1600 km s-1, comprises 21 Voigt profile components, and resides at an impact parameter of D = 58 kpc from a bright, high-mass (log M
Resolved Measurements of X CO in NGC 6946
Momose, Rieko; Scoville, Nick; Kuno, Nario +9 more
We present the largest sample to date of giant molecular clouds (GMCs) in a substantial spiral galaxy other than the Milky Way. We map the distribution of molecular gas with high resolution and image fidelity within the central 5 kpc of the spiral galaxy NGC 6946 in the 12CO (J = 1-0) transition. By combining observations from the Nobey…
New Solar Wind Diagnostic Using Both in Situ and Spectroscopic Measurements
Lepri, S. T.; Zurbuchen, T. H.; Landi, E. +1 more
We develop a new diagnostic technique that utilizes, at the same time, two completely different types of observations—in situ determinations of solar wind charge states and high-resolution spectroscopy of the inner solar corona—in order to study the temperature, density, and velocity of the solar wind as a function of height in the inner corona be…
Temporal and Spectral Evolution in X- and γ-Rays of Magnetar 1E 1547.0-5408 since its 2008 October Outburst: The Discovery of a Transient Hard Pulsed Component after its 2009 January Outburst
Kuiper, L.; Hermsen, W.; den Hartog, P. R. +1 more
The magnetar 1E 1547.0-5408 exhibited outbursts in 2008 October and 2009 January. In this paper, we present in great detail the evolution of the temporal and spectral characteristics of the persistent total and pulsed emission of 1E 1547.0-5408 between ~1 and 300 keV starting on 2008 October 3 and ending in 2011 January. We analyzed data collected…
X-Ray Observations of the Young Pulsar J1357—6429 and Its Pulsar Wind Nebula
Pavlov, George G.; Kargaltsev, Oleg; Chang, Chulhoon +1 more
We observed the young pulsar J1357—6429 with the Chandra and XMM-Newton observatories. The pulsar spectrum fits well a combination of an absorbed power-law model (Γ = 1.7 ± 0.6) and a blackbody model (kT = 140+60 - 40 eV, R ~ 2 km at the distance of 2.5 kpc). Strong pulsations with pulsed fraction of 42% ± 5%, apparently asso…
Initiation and Development of the White-light and Radio Coronal Mass Ejection on 2001 April 15
Pick, M.; Démoulin, P.; Vourlidas, A. +1 more
The 2001 April 15 event was one of the largest of the last solar cycle. A former study established that this event was associated with a coronal mass ejection (CME) observed both at white light and radio frequencies. This radio CME is illuminated by synchrotron emission from relativistic electrons. In this paper, we investigate the relation of the…
The Faint End of the Cluster-galaxy Luminosity Function at High Redshift
Wright, Edward L.; Eisenhardt, Peter R. M.; Gonzalez, Anthony H. +7 more
We measure the faint-end slope of the galaxy luminosity function (LF) for cluster galaxies at 1 < z < 1.5 using Spitzer IRAC data. We investigate whether this slope, α, differs from that of the field LF at these redshifts, and with the cluster LF at low redshifts. The latter is of particular interest as low-luminosity galaxies are expected t…
A Significant Problem with Using the Amati Relation for Cosmological Purposes
Collazzi, Andrew C.; Schaefer, Bradley E.; Goldstein, Adam +1 more
We consider the distribution of many samples of gamma-ray bursts when plotted in a diagram with their bolometric fluence (S bolo) versus the observed photon energy of peak spectral flux (E peak, obs). In this diagram, all bursts that obey the Amati relation (a luminosity relation where the total burst energy has a power-law r…