Search Publications
Evidence of Environmental Quenching at Redshift z ≈ 2
Ferguson, Henry C.; Giavalisco, Mauro; Ji, Zhiyuan +5 more
We report evidence of environmental quenching among galaxies at redshifts of ≈2, namely the probability that a galaxy quenches its star formation activity is enhanced in the regions of space in proximity of other quenched, more massive galaxies. The effect is observed as strong clustering of quiescent galaxies around quiescent galaxies on angular …
Hubble Space Telescope Wide Field Camera 3 Identifies an r p = 1 Kpc Dual Active Galactic Nucleus in the Minor Galaxy Merger SDSS J0924+0510 at z = 0.1495
Shen, Yue; Strauss, Michael A.; Greene, Jenny E. +2 more
Kiloparsec-scale dual active galactic nuclei (AGNs) are active supermassive black hole pairs co-rotating in galaxies with separations of less than a few kpc. Expected to be a generic outcome of hierarchical galaxy formation, their frequency and demographics remain uncertain. We have carried out an imaging survey with the Hubble Space Telescope (HS…
Evolution of the Solar Lyα Line Profile during the Solar Cycle
Bzowski, Maciej; Kubiak, Marzena A.; Sokół, Justyna M. +1 more
Recent studies of interstellar neutral (ISN) hydrogen observed by the Interstellar Boundary Explorer (IBEX) suggested that the present understanding of the radiation pressure acting on hydrogen atoms in the heliosphere should be revised. There is a significant discrepancy between theoretical predictions of the ISN H signal using the currently used…
Gas Contents of Galaxy Groups from Thermal Sunyaev-Zel’dovich Effects
Wang, Huiyuan; Ma, Yin-Zhe; Yang, Xiaohu +4 more
A matched filter technique is applied to the Planck all-sky Compton y-parameter map to measure the thermal Sunyaev-Zel’dovich (tSZ) effect produced by galaxy groups of different halo masses selected from large redshift surveys in the low-z universe. Reliable halo mass estimates are available for all of the groups, which allows us to bin groups of …
Time Stamps of Vertical Phase Mixing in the Galactic Disk from LAMOST/Gaia Stars
Zhang, Yong; Tian, Hai-Jun; Wu, Yue +2 more
The perturbation mechanism of the Galactic disk is a long-standing puzzle. The imprints from perturbations provide important diagnostics concerning the disk’s formation and evolution. Here we try to constrain when the vertical perturbation took place in the disk by tracking the phase-mixing history. First, we clearly depict the spiral structures o…
A Short-term ESPERTA-based Forecast Tool for Moderate-to-extreme Solar Proton Events
Laurenza, M.; Cliver, E. W.; Alberti, T.
The ESPERTA (Empirical model for Solar Proton Event Real Time Alert) forecast tool has a Probability of Detection (POD) of 63% for all >10 MeV events with proton peak intensity ≥10 pfu (i.e., ≥S1 events, S1 referring to minor storms on the NOAA Solar Radiation Storms scale), from 1995 to 2014 with a false alarm rate (FAR) of 38% and a median (m…
Discovery of a z = 7.452 High Equivalent Width Lyα Emitter from the Hubble Space Telescope Faint Infrared Grism Survey
Finkelstein, Steven L.; Koekemoer, Anton M.; Larson, Rebecca L. +19 more
We present the results of an unbiased search for Lyα emission from continuum-selected 5.6 < z < 8.7 galaxies. Our data set consists of 160 orbits of G102 slitless grism spectroscopy obtained with the Hubble Space Telescope(HST)/WFC3 as part of the Faint Infrared Grism Survey (FIGS; PI: Malhotra), which obtains deep slitless spectra of all so…
The Carnegie-Chicago Hubble Program. V. The Distances to NGC 1448 and NGC 1316 via the Tip of the Red Giant Branch
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +8 more
The Carnegie-Chicago Hubble Program (CCHP) is recalibrating the extragalactic SN Ia distance scale using exclusively Population II stars. This effort focuses on the Tip of the Red Giant Branch (TRGB) method, whose systematics are entirely independent of the Population I Cepheid-based determinations that have long served as calibrators for the SN I…
Chromospheric Heating due to Cancellation of Quiet Sun Internetwork Fields
Gošić, M.; De Pontieu, B.; Bellot Rubio, L. R. +5 more
The heating of the solar chromosphere remains one of the most important questions in solar physics. Our current understanding is that small-scale internetwork (IN) magnetic fields play an important role as a heating agent. Indeed, cancellations of IN magnetic elements in the photosphere can produce transient brightenings in the chromosphere and tr…
Formation of an Active Region Filament Driven By a Series of Jets
Cao, Wenda; Yan, Xiaoli; Wang, Jincheng +5 more
We present a formation process of a filament in active region NOAA 12574 during the period from 2016 August 11 to 12. Combining the observations of the Global Oscillation Network Group Hα, the Hida spectrum, and the Solar Dynamics Observatory/AIA 304 Å, the formation process of the filament is studied. It is found that cool material (T ∼ 104<…