Search Publications
Genesis of Interplanetary Intermittent Turbulence: A Case Study of Rope&enrope Magnetic Reconnection
Miranda, Rodrigo A.; Chian, Abraham C. -L.; Muñoz, Pablo R. +5 more
In a recent paper, the relation between current sheet, magnetic reconnection, and turbulence at the leading edge of an interplanetary coronal mass ejection was studied. We report here the observation of magnetic reconnection at the interface region of two interplanetary magnetic flux ropes. The front and rear boundary layers of three interplanetar…
The First High-phase Observations of a KBO: New Horizons Imaging of (15810) 1994 JR1 from the Kuiper Belt
Olkin, Cathy B.; Stern, S. Alan; Young, Leslie A. +12 more
NASA’s New Horizons spacecraft observed (15810) 1994 JR1, a 3:2 resonant Kuiper belt object (KBO), using the LOng Range Reconnaissance Imager (LORRI) on 2015 November 2 from a distance of 1.85 au and again on 2016 April 7 from a distance of 0.71 au. These were the first close observations of any KBO other than Pluto. Combining ground-ba…
Survival of Pure Disk Galaxies over the Last 8 Billion Years
Sachdeva, Sonali; Saha, Kanak
Pure disk galaxies without any bulge component, I.e., bulges that are neither classical nor pseudo, seem to have escaped the effects of merger activity that are inherent to hierarchical galaxy formation models as well as strong internal secular evolution. We discover that a significant fraction (∼15%-18%) of disk galaxies in the Hubble Deep Field …
Suprathermal Electrons at Saturn's Bow Shock
Coates, A. J.; Dougherty, M. K.; Fujimoto, M. +4 more
The leading explanation for the origin of galactic cosmic rays is particle acceleration at the shocks surrounding young supernova remnants (SNRs), although crucial aspects of the acceleration process are unclear. The similar collisionless plasma shocks frequently encountered by spacecraft in the solar wind are generally far weaker (lower Mach numb…
The Candidate Cluster and Protocluster Catalog (CCPC) of Spectroscopically Identified Structures Spanning 2.74 < z < 3.71
Franck, J. R.; McGaugh, S. S.
We developed a search methodology to identify galaxy protoclusters at z\gt 2.74 and implemented it on a sample of ∼14,000 galaxies with previously measured redshifts. The results of this search are recorded in the Candidate Cluster and Protocluster Catalog (CCPC). The catalog contains 12 clusters that are highly significant overdensities ({δ }
The Nucleus of the Planetary Nebula EGB 6 as a Post-Mira Binary
Bond, Howard E.; Munari, Ulisse; Ciardullo, Robin +3 more
EGB 6 is a faint, large, ancient planetary nebula (PN). Its central star, a hot DAOZ white dwarf (WD), is a prototype of a rare class of PN nuclei associated with dense, compact emission-line knots. The central star also shows excess fluxes in both the near-infrared (NIR) and mid-infrared (MIR). In a 2013 paper, we used Hubble Space Telescope (HST…
Millihertz Quasi-periodic Oscillations in 4U 1636-536: Putting Possible Constraints on the Neutron Star Size
Stiele, H.; Yu, W.; Kong, A. K. H.
Based on previous studies of quasi-periodic oscillations (QPOs) in neutron star (NS) low-mass X-ray binaries, mHz QPOs are believed to be related to “marginally stable” burning on the NS surface. Our study of phase-resolved energy spectra of these oscillations in 4U 1636-53 shows that the oscillations are not caused by variations in the blackbody …
Constraining the Solar Coronal Magnetic Field Strength using Split-band Type II Radio Burst Observations
Ramesh, R.; Kathiravan, C.; Hariharan, K. +2 more
We report on low-frequency radio (85-35 MHz) spectral observations of four different type II radio bursts, which exhibited fundamental-harmonic emission and split-band structure. Each of the bursts was found to be closely associated with a whitelight coronal mass ejection (CME) close to the Sun. We estimated the coronal magnetic field strength fro…
Dust and Polycyclic Aromatic Hydrocarbon in the Pre-transitional Disk around HD 169142
Seok, Ji Yeon; Li, Aigen
The pre-transitional disk around the Herbig Ae star HD 169142 shows a complex structure of possible ongoing planet formation in dust thermal emission from the near-infrared (IR) to millimeter wavelength range. Also, a distinct set of broad emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 µ {{m}}, commonly attributed to polycyclic arom…
The Off-centered Seyfert-like Compact Emission in the Nuclear Region of NGC 3621
Steiner, J. E.; Menezes, R. B.; da Silva, Patrícia
We analyze an optical data cube of the nuclear region of NGC 3621, taken with the integral field unit of the Gemini Multi-object Spectrograph. We found that the previously detected central line emission in this galaxy actually comes from a blob, located at a projected distance of 2.″14 ± 0.″08 (70.1 ± 2.6 pc) from the stellar nucleus. Only diffuse…