Search Publications
Projection effects in galaxy cluster samples: insights from X-ray redshifts
Lovisari, L.; Pacaud, F.; Ramos-Ceja, M. E. +3 more
Presently, the largest sample of galaxy clusters selected in X-rays comes from the ROSAT All-Sky Survey (RASS). Although there have been many interesting clusters discovered with the RASS data, the broad point spread function of the ROSAT satellite limits the attainable amount of spatial information for the detected objects. This leads to the disc…
Comet 67P/Churyumov-Gerasimenko rotation changes derived from sublimation-induced torques
Jorda, L.; Kührt, E.; Keller, H. U. +3 more
Context. The change in rotation period and the orientation of the rotation axis of comet 67P/Churyumov-Gerasimenko (67P) can be deduced with high precision from images taken by the scientific imaging instruments on board the Rosetta mission. Non-gravitational forces are a natural explanation for these data.
Aims: We describe observed changes …
A Search for Intermediate-separation Low-mass Binaries in the Orion Nebula Cluster
Reiter, Megan; Greenbaum, Alexandra; Meyer, Michael R. +3 more
We present the results of a binary population study in the Orion Nebula Cluster (ONC) using archival Hubble Space Telescope (HST) data obtained with the Advanced Camera for Surveys in Johnson V filter (HST Proposal 10246, PI M. Robberto). Young clusters and associations hold clues to the origin and properties of multiple star systems. Binaries wit…
Searching for the Donor Stars of ULX Pulsars
Harrison, F. A.; Stern, D.; Brightman, M. +3 more
We report on our search for the optical counterparts of two ultraluminous X-ray pulsars with known orbital periods, M82 X-2 and NGC 5907 X-1, in new and archival Hubble Space Telescope observations, in an effort to characterize the donor stars in these systems. We detect five near-infrared sources consistent with the position of M82 X-2 that are t…
The 3D Kinematics of Gas in the Small Magellanic Cloud
Murray, Claire E.; Peek, J. E. G.; McClure-Griffiths, N. M. +3 more
We investigate the kinematics of neutral gas in the Small Magellanic Cloud (SMC) and test the hypothesis that it is rotating in a disk. To trace the 3D motions of the neutral gas distribution, we identify a sample of young, massive stars embedded within it. These are stars with radial velocity measurements from spectroscopic surveys and proper mot…
A Catalogue of Forbush Decreases Recorded on the Surface of Mars from 2012 Until 2016: Comparison with Terrestrial FDs
Wimmer-Schweingruber, R. F.; Heber, B.; Herbst, K. +9 more
Forbush decreases (FDs) in galactic cosmic rays (GCRs) have been recorded by neutron monitors (NMs) at Earth for more than 60 years. For the past five years, with the establishment of the Radiation Assessment Detector (RAD) onboard the Mars Science Laboratory (MSL) rover Curiosity at Mars, it is possible to continuously detect, for the first time,…
Observations of Short-period Current Sheet Flapping Events in the Earth's Magnetotail
Deng, X. H.; Huang, S. Y.; Xu, S. B. +9 more
The flapping motion of the current sheet, with the period from several minutes to tens of minutes, is one common dynamic phenomenon in the planetary magnetotail. This Letter reports on one current sheet flapping event with the short semi-period of ∼6 s on 2017 July 17 in the Earth’s magnetotail for the first time using the Magnetospheric Multiscal…
The Effects of Crustal Magnetic Fields and Solar EUV Flux on Ionopause Formation at Mars
Gurnett, D. A.; Morgan, D. D.; Kopf, A. J. +5 more
We study the ionopause of Mars using a database of 6,893 ionopause detections obtained over 11 years by the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) experiment. The ionopause, in this work, is defined as a steep density gradient that appears in MARSIS remote sounding ionograms as a horizontal line at frequencies below 0.…
Determining the mass of the planetary candidate HD 114762 b using Gaia
Kiefer, Flavien
The first planetary candidate discovered by Latham et al. (1989, Nature, 339, 38) with radial velocities around a solar-like star other than the Sun, HD 114762 b, was detected with a minimum mass of 11 MJ. The small v sin i ∼ 0 km s-1 that is otherwise measured by spectral analysis indicated that this companion of a late-F su…
Understanding Formation of Young, Distributed Low-mass Stars and Clusters in the W4 Cloud Complex
Samal, Manash R.; Sharma, Saurabh; Panwar, Neelam +2 more
It is well known that most of the stars form in rich clusters. However, recent Spitzer observations have shown that a significant number of stars also form in the distributed mode; their origin is not well understood. In this work, we aim to investigate clustered and distributed modes of star formation in the W4 complex. To do so, we identified an…