Search Publications
Detection of Multiple Bipolar Flows in NGC 7027 with Submillimeter Array
Kwok, Sun; Lim, Jeremy; Hirano, Naomi +6 more
Highly collimated multiple bipolar flows are detected with a 3'' resolution in the HCO+ (J = 3-2) and HCN (J = 3-2) lines in the young planetary nebula NGC 7027 with the Submillimeter Array. The HCO+ and HCN flows coincide in location and velocity with compact and fast CO flows detected with ~6'' resolutions with other millim…
Compton Degradation of Gamma-ray Line Emission from Radioactive Isotopes in the Classical Nova V2491 Cygni
Shigeyama, Toshikazu; Suzuki, Akihiro
To account for the non-thermal emission from the classical nova V2491 Cygni, we perform a series of numerical calculations of radiative transfer of γ-ray photons from the radioactive isotope 22Na in the matter ejected from a white dwarf. Using a simple wind model for the dynamical evolution of the ejecta and a Monte Carlo code, we calcu…
Polycyclic Aromatic Hydrocarbon Emission from the Dust Lane of an Elliptical Galaxy with the Spitzer Infrared Spectrograph
Onaka, Takashi; Yamagishi, Mitsuyoshi; Sakon, Itsuki +5 more
Spitzer and AKARI observations have found that polycyclic aromatic hydrocarbons (PAHs) are present in nearby elliptical galaxies, but their spatial distributions are still unknown. In order to investigate their distributions, we performed deep spectral mapping observations of the PAH-detected elliptical galaxy NGC 4589, a merger remnant with a min…
NGC 4102: High-resolution Infrared Observations of a Nuclear Starburst Ring
Turner, Jean L.; Beck, Sara C.; Lacy, John H.
The composite galaxy NGC 4102 hosts a LINER nucleus and a starburst. We mapped NGC 4102 in the 12.8 µm line of [Ne II], using the echelon spectrometer TEXES on the NASA IRTF, to obtain a data cube with 1farcs5 spatial, and 25 km s-1 spectral, resolution. Combining near-infrared, radio, and the [Ne II] data shows that the extinctio…
Investigating the Complex X-Ray Spectrum of a Broad-Line 2MASS Red Quasar: XMM-Newton Observation of FTM 0830+3759
Nicastro, Fabrizio; Fiore, Fabrizio; Bianchi, Stefano +3 more
We report results from a 50 ks XMM-Newton observation of the dust-reddened broad-line quasar FTM 0830+3759 (z = 0.413) selected from the Faint Images of the Radio Sky at Twenty cm/Two Micron All Sky Survey red quasar survey. For this active galactic nucleus (AGN), a very short 9 ks Chandra exposure had suggested a feature-rich X-ray spectrum and H…
The Red Nova-like Variable in M31—A Blue Candidate in Quiescence
Shara, Michael M.; Prialnik, Dina; Zurek, David +2 more
M31-RV was an extraordinarily luminous (~106 L sun) eruptive variable, displaying very cool temperatures (roughly 1000 K) as it faded. While this object's peak luminosity matched or exceeded those of the brightest known classical novae, its red colors and cool spectra were very different from those of classical novae. The pho…
Green's Functions for Far-Side Seismic Images: A Polar-Expansion Approach
Pérez Hernández, F.; González Hernández, I.
We have computed seismic images of magnetic activity on the far surface of the Sun by using a seismic-holography technique. As in previous works, the method is based on the comparison of waves going in and out of a particular point in the Sun, but we have computed here Green's functions from a spherical polar expansion of the adiabatic wave equati…
Note on Travel Time Shifts Due to Amplitude Modulation in Time-Distance Helioseismology Measurements
Kosovichev, A. G.; Nigam, R.
Correct interpretation of acoustic travel times measured by time-distance helioseismology is essential to get an accurate understanding of the solar properties that are inferred from them. It has long been observed that sunspots suppress p-mode amplitude, but its implications on travel times have not been fully investigated so far. It has been fou…
Major Electron Events and Coronal Magnetic Configurations of the Related Solar Active Regions
Owen, C. J.; Li, C.; Dai, Y. +2 more
A statistical survey of 26 major electron events during the period 2002 February through the end of solar cycle 23 is presented. We have obtained electron solar onset times and the peak flux spectra for each event by fitting to a power-law spectrum truncated by an exponential high-energy tail, i.e., f(E) ∼ E^{-δ}e^{-E/E_{0}}. We also derived the c…
UV Spectral Synthesis of Vega
Fitzpatrick, E. L.
We show that the UV spectrum (1280-3200 Å) of the "superficially normal" A-star Vega, as observed by the International Ultraviolet Explorer (IUE) satellite at a resolution comparable to the star's rotational broadening width, can be fit remarkably well by a single-temperature synthetic spectrum based on LTE atmosphere models and a newly constructe…