Search Publications
Independent Evidence for Earlier Formation Epochs of Fossil Groups of Galaxies through the Intracluster Light: The Case for RX J100742.53+380046.6
Koekemoer, Anton M.; Dupke, Renato A.; Carrasco, Eleazar R. +9 more
Fossil groups (FG) of galaxies still present a puzzle to theories of structure formation. Despite the low number of bright galaxies, they have relatively high velocity dispersions and ICM temperatures often corresponding to cluster-like potential wells. Their measured concentrations are typically high, indicating early formation epochs as expected…
Multiwavelength Vertical Structure in the AU Mic Debris Disk: Characterizing the Collisional Cascade
MacGregor, Meredith A.; Hughes, A. Meredith; Wilner, David J. +9 more
Debris disks are scaled-up analogs of the Kuiper Belt in which dust is generated by collisions between planetesimals. In the collisional cascade model of debris disks, the dust lost to radiation pressure and winds is constantly replenished by grinding collisions between planetesimals. The model assumes that collisions are destructive and involve l…
Follow-up Observations of the Prolonged, Super-Eddington, Tidal Disruption Event Candidate 3XMM J150052.0+015452: the Slow Decline Continues
Ramirez-Ruiz, Enrico; Komossa, S.; Maksym, W. Peter +7 more
The X-ray source 3XMM J150052.0+015452 was discovered as a spectacular tidal disruption event candidate during a prolonged (>11 yr) outburst. It exhibited unique quasi-soft X-ray spectra of characteristic temperature kT ~ 0.3 keV for several years at the peak, but in a recent Chandra observation (10 yr into the outburst) a super-soft X-ray spec…
Testing Velocity Kinks as a Planet Detection Method: Do Velocity Kinks in Surface Gas Emission Trace Planetary Spiral Wakes in the Midplane Continuum?
Dong, Ruobing; Speedie, Jessica
Spiral density waves generated by an embedded planet are understood to cause "kinks" in observed velocity channel maps of CO surface emission by perturbing the gas motion within the spiral arms. If velocity kinks are a reliable probe of embedded planets, we should expect to see the planet-driven spiral arms in other observational tracers. We test …
ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): Evidence for a Molecular Jet Launched at an Unprecedented Early Phase of Protostellar Evolution
Sanhueza, Patricio; Kwon, Woojin; Soam, Archana +31 more
Protostellar outflows and jets play a vital role in star formation as they carry away excess angular momentum from the inner disk surface, allowing the material to be transferred toward the central protostar. Theoretically, low-velocity and poorly collimated outflows appear from the beginning of the collapse at the first hydrostatic core (FHSC) st…
A Segmented Period-Luminosity Relation for Nearby Extragalactic Delta Scuti Stars
Martínez-Vázquez, C. E.; Catelan, M.; Vivas, A. K. +1 more
The period-luminosity relations (PLRs) of Milky Way δ Scuti (δ Sct) stars have been described to the present day by a linear relation. However, when studying extragalactic systems such as the Magellanic Clouds and several dwarf galaxies, we notice for the first time a nonlinear behavior in the PLR of δ Sct stars. Using the largest sample of ~3700 …
The High-ionization IR Fine Structure Lines as Bolometric Indicators of the AGN Power: Study of the Complete 12 µm AGN Sample
Spinoglio, Luigi; Fernández-Ontiveros, Juan Antonio; Malkan, Matthew A.
The high-ionization mid-IR lines, excited in the narrow-line regions of active galactic nuclei (AGN), barely affected by stellar excitation and dust extinction, trace the AGN bolometric power. We used the complete 12 µm sample of Seyfert galaxies, for which 100/116 objects have reliable 2-10 keV observations. The [Ne V] and [O IV] mid-IR lin…
The Distance and Dynamical History of the Virgo Cluster Ultradiffuse Galaxy VCC 615
Côté, Patrick; Peng, Eric W.; Ferrarese, Laura +6 more
We use deep Hubble Space Telescope imaging to derive a distance to the Virgo Cluster ultradiffuse galaxy (UDG) VCC 615 using the tip of the red giant branch (TRGB) distance estimator. We detect 5023 stars within the galaxy, down to a 50% completeness limit of F814W ≈ 28.0, using counts in the surrounding field to correct for contamination due to b…
HST UV Spectroscopy of the Planet-hosting T Tauri Star PDS 70
Skinner, Stephen L.; Audard, Marc
We summarize Hubble Space Telescope (HST) UV observations of the weak-lined T Tauri star (wTTS) PDS 70 obtained with the Space Telescope Imaging Spectrograph. These observations provide the first far-UV (FUV) and near-UV (NUV) spectra of PDS 70. Ground-based observations have so far revealed two formative giant planets orbiting in a wide gap in it…
Flaring-associated Complex Dynamics in Two M Dwarfs Revealed by Fast, Time-resolved Spectroscopy
Wang, J.; Li, H. L.; Xin, L. P. +11 more
Habitability of an exoplanet is believed to be profoundly affected by activities of the host stars, although the related coronal mass ejections (CMEs) are still rarely detected in solar-like and late-type stars. We here report an observational study on the flares of two M dwarfs triggered by the high-cadence survey performed by the Ground-based Wi…