Search Publications
Lagrangian chaotic saddles and objective vortices in solar plasmas
Chian, Abraham C. -L.; Park, Sung-Hong; Kusano, Kanya +4 more
We report observational evidence of Lagrangian chaotic saddles in plasmas, given by the intersections of finite-time unstable and stable manifolds, using an ≈22 h sequence of spacecraft images of the horizontal velocity field of solar photosphere. A set of 29 persistent objective vortices with lifetimes varying from 28.5 to 298.3 min are detected …
The Eroding Disk of AU Mic
Augereau, J. -C.; Henning, Th.; Milli, J. +12 more
We report Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph imaging of AU Mic's debris disk from 2017 and archival data. Outward motion of the features in the southeast arm continues. At least three features have reached or exceeded projected escape velocity in the past decade, yielding a combined feature mass-loss rate of ∼1.2 × 1…
Possible Time Correlation between Jet Ejection and Mass Accretion for RW Aur A
Ohyama, Youichi; Pyo, Tae-Soo; Liu, Chun-Fan +17 more
For the active T-Taur star RW Aur A we have performed long-term (∼10 yr) monitoring observations of (1) jet imaging in the [Fe II] 1.644 µm emission line using Gemini-NIFS and VLT-SINFONI; (2) optical high-resolution spectroscopy using CFHT-ESPaDOnS; and (3) V-band photometry using the CrAO 1.25-m telescope and AAVSO. The latter two observat…
Masses of the components of SB2 binaries observed with Gaia - V. Accurate SB2 orbits for 10 binaries and masses of the components of 5 binaries
Mazeh, T.; Halbwachs, J. -L.; Arenou, F. +8 more
Double-lined spectroscopic binaries (SB2s) are one of the main sources of stellar masses, as additional observations are only needed to give the inclinations of the orbital planes in order to obtain the individual masses of the components. For this reason, we are observing a selection of SB2s using the SOPHIE spectrograph at the Haute-Provence obs…
Leveraging HST with MUSE - I. Sodium abundance variations within the 2-Gyr-old cluster NGC 1978
Martocchia, S.; Salaris, M.; Dreizler, S. +10 more
Nearly all of the well-studied ancient globular clusters (GCs), in the Milky Way and in nearby galaxies, show star-to-star variations in specific elements (e.g. He, C, N, O, Na, and Al), known as 'multiple populations' (MPs). However, MPs are not restricted to ancient clusters, with massive clusters down to ~2 Gyr showing signs of chemical variati…
On the X-Ray Spectral Energy Distributions of Star-forming Galaxies: The 0.3-30 keV Spectrum of the Low-metallicity Starburst Galaxy VV 114
Hornschemeier, Ann; Basu-Zych, Antara; Garofali, Kristen +6 more
Binary population synthesis combined with cosmological models suggests that X-ray emission from star-forming galaxies, consisting primarily of emission from X-ray binaries (XRBs) and the hot interstellar medium (ISM), could be an important, and perhaps dominant, source of heating of the intergalactic medium prior to the epoch of reionization. Howe…
Overdensity of SMGs in fields containing z ∼ 0.3 galaxies: magnification bias and the implications for studies of galaxy evolution
Bonavera, L.; Dunne, L.; Maddox, S. J. +2 more
We report a remarkable overdensity of high-redshift submillimetre galaxies (SMG), 4-7 times the background, around a statistically complete sample of twelve 250 µm selected galaxies at z = 0.35, which were targeted by ALMA in a study of gas tracers. This overdensity is consistent with the effect of lensing by the haloes hosting the target z …
Relation of Coronal Rain Originating from Coronal Condensations to Interchange Magnetic Reconnection
Peter, Hardi; Li, Leping; Chitta, Lakshmi Pradeep +1 more
Using extreme-ultraviolet images, we recently proposed a new and alternative formation mechanism for coronal rain along magnetically open field lines due to interchange magnetic reconnection. In this paper we report coronal rain at chromospheric and transition region temperatures originating from the coronal condensations facilitated by reconnecti…
A Compton-thick nucleus in the dual active galactic nuclei of Mrk 266
Inami, H.; Iwasawa, K.; Charmandaris, V. +6 more
We present the results from our analysis of NuSTAR data of the luminous infrared galaxy Mrk 266, which contains two nuclei, south-western (SW) and north-eastern (NE), which were resolved in previous Chandra imaging. Combining this with the Chandra data, we intepret the hard X-ray spectrum obtained from a NuSTAR observation to result from a steeply…
Thermal inertias of pebble-pile comet 67P/Churyumov-Gerasimenko
Ohno, Kazumasa; Arakawa, Sota
The Rosetta mission to comet 67P/Churyumov-Gerasimenko has provided new data to better understand what comets are made of. The weak tensile strength of the cometary surface materials suggests that the comet is a hierarchical dust aggregate formed through gravitational collapse of a bound clump of small dust aggregates so-called 'pebbles' in the ga…