Search Publications
Simulating Self-lensing and Eclipsing Signals due to Detached Compact Objects in the TESS Light Curves
Afshordi, Niayesh; Sajadian, Sedighe
A fraction of Galactic stars have compact companions that could be white dwarfs (WDs), neutron stars (NSs), or stellar-mass black holes (SBHs). In a detached and edge-on binary system including a main-sequence star and a compact object (denoted by WD main-sequence (WDMS), NS main-sequence (NSMS), and SBH main-sequence (BHMS) systems), the stellar …
GHOST commissioning science results - III. Characterizing an iron-poor damped Lyman α system
Simpson, Chris; Hayes, Christian R.; Sestito, Federico +20 more
The Gemini High-resolution Optical SpecTrograph (GHOST) is a new Echelle spectrograph available on the Gemini-South telescope as of Semester 2024A. We present the first high-resolution spectrum of the quasar J1449-1227 (redshift zem = 3.27) using data taken during the commissioning of GHOST. The observed quasar hosts an intervening iron…
Deciphering Martian Flood Infiltration Processes at Hebrus Valles: Insights From Laboratory Experiments and Remote Sensing Observations
Séjourné, A.; Kargel, J. S.; Costard, F. +2 more
In evaluating the unique geomorphology of Hebrus Valles on Mars, an outflow channel southeast of Utopia Planitia, we investigated the role of fluvial dynamics in forming subsurface conduits. Unlike typical Martian channels that terminate under younger sediment rocks, Hebrus Valles retains its downstream features, thus offering a window into surfac…
Resolving a Candidate Dual Active Galactic Nucleus with ∼100 pc Separation in MCG-03-34-64
Turner, T. J.; Kraemer, S. B.; Braito, V. +4 more
We report the serendipitous multiwavelength discovery of a candidate dual black hole system with a separation of ∼100 pc, in the gas-rich luminous infrared galaxy MCG-03-34-64 (z = 0.016). Hubble Space Telescope/Advanced Camera for Surveys observations show three distinct optical centroids in the [O III] narrow-band and F814W images. Subsequent an…
Two mini-Neptunes transiting the adolescent K-star HIP 113103 confirmed with TESS and CHEOPS
Pallé, E.; Zhang, H.; Winn, J. N. +31 more
We report the discovery of two mini-Neptunes in near 2:1 resonance orbits (P = 7.610303 d for HIP 113103 b and P = 14.245651 d for HIP 113103 c) around the adolescent K-star HIP 113103 (TIC 121490076). The planet system was first identified from the TESS mission, and was confirmed via additional photometric and spectroscopic observations, includin…
Combined JWST–MUSE Integral Field Spectroscopy of the Most Luminous Quasar in the Local Universe, PDS 456
Veilleux, Sylvain; Zakamska, Nadia L.; Liu, Weizhe +5 more
Fast accreting, extremely luminous quasars contribute heavily to the feedback process within galaxies. While these systems are most common at cosmic noon (z ∼ 2), here we choose to study PDS 456, an extremely luminous (L bol ∼ 1047 erg s‑1) but nearby (z ∼ 0.185) quasar where the physics of feedback can be studied …
Magnetic fields and electric currents around the dayside magnetopause as inferred from data-constrained modeling
Semenov, V. S.; Erkaev, N. V.; Tsyganenko, N. A. +1 more
Based on a new mathematical framework and large multi-year multi-mission data sets, we reconstruct electric currents and magnetic fields around the dayside magnetopause and their dependence on the incoming solar wind, IMF, and geodipole tilt. The model architecture builds on previously developed mathematical frameworks and includes two separate bl…
What drives the wheels of evolution in NGC 1512?. A UVIT study
Mathew, Blesson; Kartha, Sreeja S.; George, Koshy +4 more
Context. Environmental and secular processes play a pivotal role in the evolution of galaxies. These can be external processes such as interactions or internal processes linked to the action of bar, bulge, and spiral structures. Ongoing star formation in spiral galaxies can be affected by these processes. By studying the star formation progression…
Mapping and characterizing magnetic fields in the Rho Ophiuchus-A molecular cloud with SOFIA/HAWC+
Diep, Pham Ngoc; Hoang, Thiem; Ngoc, Nguyen Bich +10 more
Context. Together with gravity, turbulence, and stellar feedback, magnetic fields (B-fields) are thought to play a critical role in the evolution of molecular clouds and star formation processes. The polarization of thermal dust emission is a popular tracer of B-fields in star-forming regions. Aims. We aim to map the morphology and measure the str…
CME-Flare Association and the Role of Reconnection in CME Acceleration
Reva, Anton; Kirichenko, Alexey; Bogachev, Sergey +1 more
The association of coronal mass ejections (CMEs) with flares is related to the question of whether reconnection is necessary for the CME eruption. Indeed, if reconnection happens during a CME eruption, the plasma is heated, which can be observed as a flare. In this work, we study the CME-flare association using data obtained with the Mg XII spectr…