Search Publications
Discovery of Extended Infrared Emission around the Neutron Star RXJ0806.4-4123
Luhman, K. L.; Pavlov, G. G.; Williams, C. C. +3 more
Following up on a faint detection of a near-infrared (NIR) source at the position of the X-ray thermal isolated neutron star RX J0806.4-4123, we present new Hubble Space Telescope observations in the H-band. The NIR source is unambiguously detected with a Vega magnitude of 23.7 ± 0.2 (flux density of 0.40 ± 0.06 µJy at λ = 1.54 µm). Th…
Evidence of Twisting and Mixed-polarity Solar Photospheric Magnetic Field in Large Penumbral Jets: IRIS and Hinode Observations
Tiwari, Sanjiv K.; Winebarger, Amy R.; De Pontieu, Bart +4 more
A recent study using Hinode (Solar Optical Telescope/Filtergraph [SOT/FG]) data of a sunspot revealed some unusually large penumbral jets that often repeatedly occurred at the same locations in the penumbra, namely, at the tail of a penumbral filament or where the tails of multiple penumbral filaments converged. These locations had obvious photosp…
Black Holes and Neutron Stars in Nearby Galaxies: Insights from NuSTAR
Wik, D. R.; Lehmer, B. D.; Hornschemeier, A. E. +8 more
Nearby galaxy surveys have long classified X-ray binaries (XRBs) by the mass category of their donor stars (high-mass and low-mass). The NuSTAR observatory, which provides imaging data at E > 10 keV, has enabled the classification of extragalactic XRBs by their compact object type: neutron star (NS) or black hole (BH). We analyzed NuSTAR/Chandr…
2004 EW95: A Phyllosilicate-bearing Carbonaceous Asteroid in the Kuiper Belt
Fraser, Wesley C.; Brown, Michael E.; Puzia, Thomas H. +2 more
Models of the Solar System’s dynamical evolution predict the dispersal of primitive planetesimals from their formative regions among the gas-giant planets due to the early phases of planetary migration. Consequently, carbonaceous objects were scattered both into the outer asteroid belt and out to the Kuiper Belt. These models predict that the Kuip…
HST/GHRS Observations of Cool, Low-gravity Stars. VI. Mass-loss Rates and Wind Parameters for M Giants
Carpenter, Kenneth G.; Nielsen, Krister E.; Rau, Gioia +1 more
The photon-scattering winds of M giants absorb parts of the chromospheric emission lines and produce self-reversed spectral features in high-resolution Hubble Space Telescope (HST)/GHRS spectra. These spectra provide an opportunity to assess fundamental parameters of the wind, including flow and turbulent velocities, the optical depth of the wind …
Spectroscopic Confirmation and Velocity Dispersions for 20 Planck Galaxy Clusters at 0.16 < z < 0.78
Chary, Ranga-Ram; Stern, Daniel; Shim, Hyunjin +8 more
We present Gemini and Keck spectroscopic redshifts and velocity dispersions for 20 clusters detected via the Sunyaev-Zel’dovich (SZ) effect by the Planck space mission, with estimated masses in the range 2.3× {10}14 {M}⊙ < {M}500{Pl}< 9.4× {10}14 {M}⊙ . Cluster members were se…
Resurrecting the Power-law, Intermediate, and Logamediate Inflations in the DBI Scenario with Constant Sound Speed
Karami, Kayoomars; Rezazadeh, Kazem; Amani, Roonak +1 more
We investigate the power-law, intermediate, and logamediate inflationary models in the framework of DBI non-canonical scalar field with constant sound speed. In the DBI setting, we first represent the power spectrum of both scalar density and tensor gravitational perturbations. Then, we derive different inflationary observables including the scala…
On the Transition of the Galaxy Quenching Mode at 0.5 < z < 1 in CANDELS
Barro, Guillermo; Pérez-González, Pablo G.; Bell, Eric F. +19 more
We investigate the galaxy quenching process at intermediate redshift using a sample of ∼4400 galaxies with M * > 109 M ⊙ between redshift 0.5 and 1.0 in all five CANDELS fields. We divide this sample, using the integrated specific star formation rate (sSFR), into four subgroups: star-forming galaxies (SFGs) abov…
Jet-related Excitation of the [C II] Emission in the Active Galaxy NGC 4258 with SOFIA
Appleton, P. N.; Guillard, P.; Togi, A. +7 more
We detect widespread [C II] 157.7 µm emission from the inner 5 kpc of the active galaxy NGC 4258 with the SOFIA integral field spectrometer FIFI-LS. The emission is found to be associated with warm H2, distributed along and beyond the end of the southern jet, in a zone known to contain shock-excited optical filaments. It is also a…
What We Learn from the X-Ray Grating Spectra of Nova SMC 2016
Rauch, T.; Della Valle, M.; Behar, E. +17 more
Nova SMC 2016 has been the most luminous nova known in the direction of the Magellanic Clouds. It turned into a very luminous supersoft X-ray source between days 16 and 28 after the optical maximum. We observed it with Chandra, the HRC-S camera, and the Low Energy Transmission Grating on 2016 November and 2017 January (days 39 and 88 after optical…