Search Publications
Morpho-kinematic Modeling of the Expanding Ejecta of the Extremely Slow Nova V1280 Scorpii
Maehara, Hiroyuki; Sakon, Itsuki; Watanabe, Makoto +10 more
Knowledge of the morphology of nova ejecta is essential for fully understanding the physical processes involved in nova eruptions. We studied the 3D morphology of the expanding ejecta of the extremely slow nova V1280 Sco with a unique light curve. Synthetic line profile spectra were compared to the observed [O III] λλ4959, 5007 and [N II] λ5755 em…
Density Turbulence and the Angular Broadening of Outer Heliospheric Radio Sources at High Latitudes and in the Ecliptic Plane
Cairns, Iver H.; Adhikari, L.; Tasnim, Samira +1 more
Density irregularities are responsible for the scattering of radio waves in the solar wind and astrophysical plasmas. These irregularities significantly affect the inferred physical properties of radio sources, such as size, direction, and intensity. We present here a theory of angular broadening due to the scattering of radio waves by density irr…
Widespread 1-2 MeV Energetic Particles Associated with Slow and Narrow Coronal Mass Ejections: Parker Solar Probe and STEREO Measurements
Lugaz, Noé; Zhuang, Bin; Lario, David
Suprathermal ions in the corona are thought to serve as seed particles for large gradual solar energetic particle (SEP) events associated with fast and wide coronal mass ejections (CMEs). A better understanding of the role of suprathermal particles as seed populations for SEP events can be made by using observations close to the Sun. We study a se…
Polarization Spectrum of Near-Infrared Zodiacal Light Observed with CIBER
Shirahata, Mai; Cooray, Asantha; Matsuura, Shuji +14 more
We report the first measurement of the zodiacal light (ZL) polarization spectrum in the near-infrared between 0.8 and 1.8 µm. Using the low-resolution spectrometer on board the Cosmic Infrared Background Experiment, calibrated for absolute spectrophotometry and spectropolarimetry, we acquire long-slit polarization spectral images of the tota…
Infrared Excess of a Large OB Star Sample
Jiang, Biwei; Deng, Dingshan; Wang, Yuxi +2 more
The infrared (IR) excess from OB stars is commonly considered to be a contribution from ionized stellar wind or circumstellar dust. With the newly published Large Sky Area Multi-Object Fiber Spectroscopy Telescope (LAMOST)-OB catalog and Galactic O-Star Spectroscopic Survey data, this work steps further on understanding the IR excess of OB stars. …
Effects of Spectral Resolution on Simple Magnetic Field Diagnostics of the Mg II H and K Lines
Rempel, Matthias; Centeno, Rebecca; del Pino Alemán, Tanausú +1 more
We study the effects of finite spectral resolution on the magnetic field values retrieved through the weak-field approximation (WFA) from the cores of the Mg II h and k lines. The retrieval of the line-of-sight component of the magnetic field, B LOS, from synthetic spectra generated in a uniformly magnetized FAL-C atmosphere is accurate…
A Model-based Technique for Ad Hoc Correction of Instrumental Polarization in Solar Spectropolarimetry
Schad, Thomas A.; Tarr, Lucas A.; Jaeggli, Sarah A. +1 more
We present a new approach for correcting instrumental polarization by modeling the nondepolarizing effects of a complex series of optical elements to determine physically realizable Mueller matrices. Provided that the Mueller matrix of the optical system can be decomposed into a general elliptical diattenuator and general elliptical retarder, it i…
Gamma-Ray Orbital Modulation of the Transitioning Millisecond Pulsar Binary XSS J12270-4859
An, Hongjun
We report on gamma-ray orbital modulation of the transitioning MSP binary XSS J12270-4859 detected in the Fermi Large Area Telescope (LAT) data. We use long-term optical data taken with the XMM-Newton OM and the Swift UltraViolet Optical Telescope to inspect radio timing solutions that are limited to relatively short time intervals and find that e…
Simultaneous High Dynamic Range Algorithm, Testing, and Instrument Simulation
Chamberlin, Phillip C.; Jin, Meng; Woods, Thomas N. +4 more
Within an imaging instrument's field of view, there may be many observational targets of interest. Similarly, within a spectrograph's bandpass, there may be many emission lines of interest. The brightness of these targets and lines can be orders of magnitude different, which poses a challenge to instrument and mission design. A single exposure can…
LEGA-C: Analysis of Dynamical Masses from Ionized Gas and Stellar Kinematics at z 0.8
Bell, Eric F.; D'Eugenio, Francesco; Franx, Marijn +12 more
We compare dynamical mass estimates based on spatially extended stellar and ionized gas kinematics (M dyn,* and M dyn,eml, respectively) of 157 star-forming galaxies at 0.6 ≤ z < 1. Compared with z ~ 0, these galaxies have enhanced star formation rates, with stellar feedback likely affecting the dynamics of the gas. We us…