Search Publications
The Random Transiter - EPIC 249706694/HD 139139
Dai, F.; Vanderburg, A.; Jenkins, J. M. +16 more
We have identified a star, EPIC 249706694 (HD 139139), that was observed during K2 Campaign 15 with the Kepler extended mission that appears to exhibit 28 transit-like events over the course of the 87-d observation. The unusual aspect of these dips, all but two of which have depths of 200 ± 80 ppm, is that they exhibit no periodicity, and their ar…
Changes in Solar Rotation over Two Solar Cycles
Basu, Sarbani; Antia, H. M.
We use helioseismic data from ground- and space-based instruments to analyze how solar rotation has changed since the beginning of solar Cycle 23 with emphasis on studying the differences between Cycles 23 and 24. We find that the nature of solar rotation is indeed different for the two cycles. While the changes in the latitudinally independent co…
The complex case of MACS J0717.5+3745 and its extended filament: intra-cluster light, galaxy luminosity function, and galaxy orientations
Adami, C.; Martinet, N.; Durret, F. +3 more
Context. The properties of galaxies are known to be affected by their environment, but although galaxies in clusters and groups have been quite thoroughly investigated, little is known about galaxies belonging to filaments of the cosmic web, or about the properties of the filaments themselves.
Aims: Here we investigate the properties of the r…
Low-frequency X-ray timing with Gaussian processes and reverberation in the radio-loud AGN 3C 120
Wilkins, D. R.
A framework is developed to perform Fourier-domain timing analysis on X-ray light curves with gaps, employing Gaussian processes to model the probability distribution underlying the observed time series from which continuous samples can be drawn. A technique is developed to measure X-ray reverberation from the inner regions of accretion discs arou…
Noncircular Motions in the Outer Perseus Spiral Arm
Menten, Karl M.; Reid, Mark J.; Sakai, Nobuyuki +2 more
We report measurements of parallax and proper motion for five 6.7 GHz methanol maser sources in the outer regions of the Perseus arm as part of the BeSSeL Survey of the Galaxy. By combining our results with previous astrometric results, we determine an average spiral arm pitch angle of 9.°2 ± 1.°5 and an arm width of 0.39 kpc for this spiral arm. …
How the power spectrum of dust continuum images may hide the presence of a characteristic filament width
Miville-Deschênes, M. -A.; André, Ph.; Arzoumanian, D. +6 more
Context. Herschel observations of interstellar clouds support a paradigm for star formation in which molecular filaments play a central role. One of the foundations of this paradigm is the finding, based on detailed studies of the transverse column density profiles observed with Herschel, that nearby molecular filaments share a common inner width …
Signatures of Tidal Disruption in Ultra-faint Dwarf Galaxies: A Combined HST, Gaia, and MMT/Hectochelle Study of Leo V
Caldwell, Nelson; Strader, Jay; Seth, Anil C. +10 more
The ultra-faint dwarf galaxy Leo V has shown both photometric overdensities and kinematic members at large radii, along with a tentative kinematic gradient, suggesting that it may have undergone a close encounter with the Milky Way. We investigate these signs of disruption through a combination of (i) high precision photometry obtained with the Hu…
Nuclear kinematics in nearby AGN - I. An ALMA perspective on the morphology and kinematics of the molecular CO(2-1) emission
Storchi-Bergmann, T.; Schnorr-Müller, A.; Robinson, A. +6 more
We present the molecular gas morphology and kinematics of seven nearby Seyfert galaxies obtained from our 230 GHz ALMA observations. The CO J = 2-1 kinematics within the inner ∼30 arcsec (≲9 kpc) reveals rotation patterns that have been explored using the Bertola rotation model and a modified version of the Kinemetry package. The latter algorithm …
Resolved Molecular Gas and Star Formation Properties of the Strongly Lensed z = 2.26 Galaxy SDSS J0901+1814
Wilner, David J.; Keeton, Charles R.; Lutz, Dieter +8 more
We present ∼1″ resolution (∼2 kpc in the source plane) observations of the CO (1-0), CO (3-2), Hα, and [N II] lines in the strongly lensed z = 2.26 star-forming galaxy SDSS J0901+1814. We use these observations to constrain the lensing potential of a foreground group of galaxies, and our source-plane reconstructions indicate that SDSS J0901+1814 i…
Identifying Galactic Halo Substructure in 6D Phase Space Using ∼13,000 LAMOST K Giants
Tian, Hao; Zhao, Gang; Li, Chengdong +6 more
We construct a large halo K-giant sample by combining the positions, distances, radial velocities, and metallicities of over 13,000 LAMOST DR5 halo K giants with the Gaia DR2 proper motions, which covers a Galactocentric distance range of 5-120 kpc. Using a position-velocity clustering estimator (the 6Distance), we statistically quantify the prese…