Search Publications
Solar Filament Eruptions as Precursors to Flare-CME Events: Establishing the Temporal Connection
Nandy, Dibyendu; Srivastava, Nandita; Sinha, Suvadip
Elongated structures on the Sun’s surface known as filaments are known to have a connection with energetic events of space weather consequence (flares and coronal mass ejections (CMEs)). In this work, we explore the connection between the eruptive dynamics of filaments and the initiation of solar flares and CMEs. We estimate the filament eruption …
Multiwavelength Analysis of the Merging Galaxy Cluster A115
van Weeren, R. J.; Dawson, W. A.; Jee, M. James +4 more
A115 is a merging galaxy cluster at z ∼ 0.2 with a number of remarkable features, including a giant (∼2.5 Mpc) radio relic, two asymmetric X-ray peaks with trailing tails, and a peculiar line-of-sight velocity structure. We present a multiwavelength study of A115 using optical imaging data from Subaru, X-ray data from Chandra, and spectroscopic da…
Surveying the Giant H II Regions of the Milky Way with SOFIA. I. W51A
Lim, Wanggi; De Buizer, James M.
We discuss the first results from our mid-infrared (MIR) imaging survey of Milky Way Giant H II (GH II) regions with our detailed analysis of W51A, which is one of the largest GH II regions in our Galaxy. We used the FORCAST instrument on the Stratospheric Observatory For Infrared Astronomy (SOFIA) to obtain 20 and 37 µm images of the centra…
PSR J1306-40: An X-Ray Luminous Redback with an Evolved Companion
Strader, Jay; Chomiuk, Laura; Shishkovsky, Laura +1 more
PSR J1306-40 is a millisecond pulsar (MSP) binary with a non-degenerate companion in an unusually long ∼1.097 day orbit. We present new optical photometry and spectroscopy of this system, and model these data to constrain fundamental properties of the binary such as the component masses and distance. The optical data imply a minimum neutron star m…
Evidence of Nonluminous Matter in the Center of M62
Colpi, Monica; Possenti, Andrea; Abbate, Federico +1 more
Theoretical models suggest that intermediate-mass black holes (IMBHs) may form and reside in the centers of globular clusters. IMBHs are still elusive to observations, but the accelerations of pulsars may bring along a unique fingerprint of their presence. In this work, we focus on the pulsars in the globular cluster M62. Using the new distance of…
An ALMA Study of the FU Ori-type Object V900 Mon: Implications for the Progenitor
Dong, Ruobing; Takami, Michihiro; Ábrahám, Péter +13 more
We present ALMA observations of 12CO, 13CO, and C18O J = 2-1 lines and the 230 GHz continuum for the FU Ori-type object (FUor) V900 Mon (d ∼ 1.5 kpc), for which the accretion burst was triggered between 1953 and 2009. We identified CO emission associated with a molecular bipolar outflow extending up to an ∼104…
Cloud Atlas: Variability in and out of the Water Band in the Planetary-mass HD 203030B Points to Cloud Sedimentation in Low-gravity L Dwarfs
Schneider, Glenn; Metchev, Stanimir; Apai, Dániel +11 more
We use the Wide Field Camera 3 on the Hubble Space Telescope to spectrophotometrically monitor the young L7.5 companion HD 203030B. Our time series reveal photometric variability at 1.27 and 1.39 µm on timescales compatible with rotation. We find a rotation period of {7.5}-0.5+0.6 hr: comparable to those observed in oth…
Application of Clumpy Torus Model to Broadband X-Ray Spectra of Two Seyfert 1 Galaxies: IC 4329A and NGC 7469
Tanimoto, Atsushi; Ueda, Yoshihiro; Kawaguchi, Toshihiro +2 more
We apply a new X-ray clumpy torus model, XCLUMPY, in which the clump distribution is assumed to be the same as that in the infrared clumpy torus model (CLUMPY) by Nenkova et al., to the broadband X-ray spectra of type-1 active galactic nuclei (AGNs) for the first time. We analyze the archival data of IC 4329A and NGC 7469 observed with NuSTAR/Suza…
HALO7D I. The Line-of-sight Velocities of Distant Main-sequence Stars in the Milky Way Halo
Barro, Guillermo; Guhathakurta, Puragra; Kirby, Evan N. +5 more
The Halo Assembly in Lambda-CDM: Observations in 7 Dimensions (HALO7D) data set consists of Keck II/DEIMOS spectroscopy and Hubble Space Telescope-measured proper motions of Milky Way halo main-sequence turnoff stars in the CANDELS fields. In this paper, we present the spectroscopic component of this data set and discuss target selection, observin…
A Closer Look at Some Gas-phase Depletions in the ISM: Trends for O, Ge, and Kr versus {F}_{* }, f(H2), and Starlight Intensity
Jenkins, Edward B.
In a survey of archived ultraviolet spectra of 100 stars recorded by the echelle spectrograph of the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we measure the strengths of the weak absorption features of O I, Ge II, and Kr I in the interstellar medium. Our objective is to undertake an investigation that goes beyond earlier…