Search Publications
Missions
Journals
Publication Years
Herschel Observations of Disks around Late-type Stars
Gizis, John E.; Plavchan, Peter; Matrá, Luca +9 more
A set of twenty late-type (K5-M5) stars were observed with the Herschel Space Observatory at 100 and 160 microns with the goal of searching for far-infrared excesses indicative of the presence of circumstellar disks. Out of this sample, four stars (TYC 7443-1102-1, TYC 9340-437-1, GJ 784 and GJ 707) have infrared excesses above their stellar photo…
Variable stars in the Sh 2-170 H II region
Matsunaga, N.; Sharma, Saurabh; Sinha, Tirthendu +7 more
We present multi-epoch deep (∼20 mag) Ic-band photometric monitoring of the Sh 2-170 star-forming region to understand the variability properties of pre-main-sequence (PMS) stars. We report identification of 47 periodic and 24 non-periodic variable stars with periods and amplitudes ranging from ∼4 h to 18 d and from ∼0.1 to 2.0 mag, res…
The large amplitude X-ray variability in NGC 7589: possible evidence for accretion mode transition
Liu, Zhu; Yuan, Weimin; Liu, He-Yang +2 more
We report the discovery of large amplitude X-ray variability in the low-luminosity active galactic nucleus NGC 7589, and present possible observational evidence for accretion mode transition in this source. Long-term X-ray flux variations by a factor of more than 50 are found using X-ray data obtained by Swift/X-Ray Telescope and XMM-Newton over 1…
Low Water Outgassing from (24) Themis and (65) Cybele: 3.1 µm Near-IR Spectral Implications
Valtchanov, I.; Fornasier, S.; Küppers, M. +9 more
Asteroids (24) Themis and (65) Cybele have an absorption feature at 3.1 µm reported to be directly linked to surface water ice. We searched for water vapor escaping from these asteroids with the Herschel Space Observatory Heterodyne Instrument for the Far Infrared. While no H2O line emission was detected, we obtain sensitive 3σ wa…
A new study of the spectroscopic binary 7 Vul with a Be star primary
Harmanec, P.; Labadie-Bartz, J.; Yang, S. +5 more
We confirmed the binary nature of the Be star 7 Vul, derived a more accurate spectroscopic orbit with an orbital period of 69.d4212±0.d0034, and improved the knowledge of the basic physical elements of the system. Analyzing available photometry and the strength of the Hα emission, we also document the lo…
Observations of GRO J1744-28 in quiescence with XMM-Newton
Tsygankov, S.; Santangelo, A.; Doroshenko, V. +3 more
We report on the deep observations of the "bursting pulsar" GRO J1744-28, which were performed with XMM-Newton and aimed to clarify the origin of its X-ray emission in quiescence. We detect the source at a luminosity level of ∼1034 erg s-1 with an X-ray spectrum that is consistent with the power law, blackbody, or accretion-h…
The impact of wind scalings on stellar growth and the baryon cycle in cosmological simulations
Kollmeier, Juna A.; Davé, Romeel; Weinberg, David H. +5 more
Many phenomenologically successful cosmological simulations employ kinetic winds to model galactic outflows. Yet systematic studies of how variations in kinetic wind scalings might alter observable galaxy properties are rare. Here we employ GADGET-3 simulations to study how the baryon cycle, stellar mass function, and other galaxy and CGM predicti…
AGN feedback in the FR II galaxy 3C 220.1
Jones, Christine; Nulsen, Paul E. J.; Forman, William R. +6 more
We present results from a deep (174 ks) Chandra observation of the FR-II radio galaxy 3C 220.1, the central brightest cluster galaxy (BCG) of a kT ∼ 4 keV cluster at z = 0.61. The temperature of the hot cluster medium drops from ∼5.9 to ∼3.9 keV at ∼35 kpc radius, while the temperature at smaller radii may be substantially lower. The central activ…
Spatial Distribution of the Origin of Umbral Waves in a Sunspot Umbra
Kilcik, Ali; Yurchyshyn, Vasyl; Lim, Eun-Kyung +2 more
Umbral flashes (UFs) are emissions in the core of chromospheric lines caused by upward propagating waves steepening into shocks. UFs are followed by an expanding blueshifted umbral wave and redshifted plasma returning to the initial state. Here we use 5 s cadence images acquired at ±0.04 nm off the H ${}_{\alpha }$ line center by the Visible Imagi…
A two-sided but significantly beamed jet in the supercritical accretion quasar IRAS F11119+3257
Paragi, Zsolt; Yang, Jun; An, Tao +3 more
Highly accreting quasars are quite luminous in the X-ray and optical regimes; while, they tend to become radio quiet and have optically thin radio spectra. Among the known quasars, IRAS F11119+3257 is a supercritical accretion source because it has a bolometric luminosity slightly above the Eddington limit and extremely powerful X-ray outflows. To…