Search Publications
Measuring the Milky Way Vertical Potential with the Phase Snail in a Model-independent Way
Mao, Shude; Liu, Chao; Shen, Juntai +2 more
The vertical phase-space spiral (snail) is a direct sign of disequilibrium of the Milky Way's disk. Nevertheless, the wrapping of the phase snail contains information on the vertical potential. We propose a novel method to measure the vertical potential utilizing the intersections between the snail and z/V z axes, for which we know th…
A 1.55 R⊕ habitable-zone planet hosted by TOI-715, an M4 star near the ecliptic South Pole
Triaud, Amaury H. M. J.; Latham, David W.; Stassun, Keivan G. +48 more
A new generation of observatories is enabling detailed study of exoplanetary atmospheres and the diversity of alien climates, allowing us to seek evidence for extraterrestrial biological and geological processes. Now is therefore the time to identify the most unique planets to be characterized with these instruments. In this context, we report on …
JWST Observations of Young protoStars (JOYS): HH211: Textbook case of a protostellar jet and outflow
Östlin, G.; Güdel, M.; Ray, T. P. +22 more
Context. Due to the high visual extinction and lack of sensitive mid-infrared (MIR) telescopes, the origin and properties of outflows and jets from embedded Class 0 protostars are still poorly constrained. Aims. We aim to characterise the physical, kinematic, and dynamical properties of the HH 211 jet and outflow, one of the youngest protostellar …
Evolution of Flare Activity in GKM Stars Younger Than 300 Myr over Five Years of TESS Observations
France, Kevin; Gagné, Jonathan; Feinstein, Adina D. +2 more
Stellar flares are short-duration (< hours) bursts of radiation associated with surface magnetic reconnection events. Stellar magnetic activity generally decreases as a function of both the age and Rossby number, R 0, a measure of the relative importance of the convective and rotational dynamos. Young stars (<300 Myr) have typical…
Signatures of Tidal Disruption of the Hercules Ultrafaint Dwarf Galaxy
Erkal, Denis; Geha, Marla; Frebel, Anna +6 more
The Hercules ultrafaint dwarf galaxy (UFD) has long been hypothesized to be tidally disrupting, yet no conclusive evidence has been found for tidal disruption owing partly to difficulties in identifying Hercules member stars. In this work, we present a homogeneous reanalysis of new and existing observations of Hercules, including the detection of …
Multiwavelength detection of an ongoing FUOr-type outburst on a low-mass YSO
Minniti, D.; Bayo, A.; Alonso-García, J. +13 more
During the pre-main-sequence evolution, Young Stellar Objects (YSOs) assemble most of their mass during the episodic accretion process. The rarely seen FUOr-type events are valuable laboratories to investigate the outbursting nature of YSOs. Here, we present multiwavelength detection of a high-amplitude eruptive source in the young open cluster Vd…
Growing local arm inferred by the breathing motion
Kawata, Daisuke; Fujii, Michiko S.; Baba, Junichi +1 more
Theoretical models of spiral arms suggest that the spiral arms provoke a vertical bulk motion in disc stars. By analysing the breathing motion, a coherent asymmetric vertical motion around the mid-plane of the Milky Way disc, with Gaia DR3, we found that a compressing breathing motion presents along the Local arm. On the other hand, with an N-body…
Accretion and obscuration in merger-dominated luminous red quasars
Piconcelli, Enrico; Lacy, Mark; LaMassa, Stephanie +2 more
We present an analysis of the X-ray properties of 10 luminous, dust-reddened quasars from the FIRST-2MASS (F2M) survey based on new and archival Chandra observations. These systems are interpreted to be young, transitional objects predicted by merger-driven models of quasar/galaxy co-evolution. The sources have been well studied from the optical t…
The APO-K2 Catalog. II. Accurate Stellar Ages for Red Giant Branch Stars across the Milky Way
García, Rafael A.; Stello, Dennis; Beaton, Rachael L. +11 more
We present stellar age determinations for 4661 red giant branch stars in the APO-K2 catalog, derived using mass estimates from K2 asteroseismology from the K2 Galactic Archaeology Program and elemental abundances from the Apache Point Galactic Evolution Experiment survey. Our sample includes 17 of the 19 fields observed by K2, making it one of the…
AT 2023lli: A Tidal Disruption Event with Prominent Optical Early Bump and Delayed Episodic X-Ray Emission
Liu, Hao; Liu, Wei; Kong, Xu +42 more
High-cadence, multiwavelength observations have continuously revealed the diversity of tidal disruption events (TDEs), thus greatly advancing our knowledge and understanding of TDEs. In this work, we conducted an intensive optical-UV and X-ray follow-up campaign of TDE AT 2023lli and found a remarkable month-long bump in its UV/optical light curve…