Search Publications
Discovery of an Edge-on Circumstellar Debris Disk around BD+45° 598: A Newly Identified Member of the β Pictoris Moving Group
Mamajek, Eric; Hinkley, Sasha; Matthews, Brenda +25 more
We report the discovery of a circumstellar debris disk viewed nearly edge-on and associated with the young, K1 star BD+45° 598 using high-contrast imaging at 2.2 µm obtained at the W.M. Keck Observatory. We detect the disk in scattered light with a peak significance of ∼5σ over three epochs, and our best-fit model of the disk is an almost ed…
MMX geodesy investigations: science requirements and observation strategy
Kouyama, Toru; Baresi, Nicola; Hirata, Naru +10 more
In order to investigate the origin of Phobos and Deimos, the Japanese Martian Moons eXploration (MMX) mission is scheduled for launch in 2024. MMX will make comprehensive remote-sensing measurements of both moons and return regolith samples from Phobos to Earth. Geodetic measurements of gravity, shape, and rotation parameter of a body provides con…
The shape and scatter of the galaxy main sequence for massive galaxies at cosmic noon
Papovich, Casey; Finkelstein, Steven L.; Stevans, Matthew L. +7 more
We present the main sequence for all galaxies and star-forming galaxies for a sample of 28 469 massive (M⋆ ≥ 1011 M⊙) galaxies at cosmic noon (1.5 < z < 3.0), uniformly selected from a 17.5 deg2 area (0.33 Gpc3 comoving volume at these redshifts). Our large sample allows for a novel appr…
Multiple Sources of Solar High-energy Protons
Yu, Sijie; Vainio, Rami; Gary, Dale E. +6 more
During the 24th solar cycle, the Fermi Large Area Telescope (LAT) has observed a total of 27 solar flares possessing delayed γ-ray emission, including the exceptionally well-observed flare and coronal mass ejection (CME) on 2017 September 10. Based on the Fermi/LAT data, we plot, for the first time, maps of possible sources of the delayed >100 …
Is Flare Ribbon Fine Structure Related to Tearing in the Flare Current Sheet?
Wyper, P. F.; Pontin, D. I.
Observations of solar flare ribbons show significant fine structure in the form of breaking wavelike perturbations and spirals. The origin of this structure is not well understood, but one possibility is that it is related to the tearing instability in the flare current sheet. Here we study this connection by constructing an analytical 3D magnetic…
The Timing of Alluvial Fan Formation on Mars
Wilson, Sharon A.; Kite, Edwin S.; Holo, Samuel J. +1 more
The history of rivers on Mars is an important constraint on Martian climate evolution. The timing of relatively young, alluvial fan-forming rivers is especially important, as Mars's Amazonian atmosphere is thought to have been too thin to consistently support surface liquid water. Previous regional studies suggested that alluvial fans formed prima…
Compact galaxies and the size-mass galaxy distribution from a colour-selected sample at 0.04 < z < 0.15 supplemented by ugrizYJHK photometric redshifts
Baldry, Ivan K.; Sullivan, Tricia; Rani, Raffaele +1 more
The size-mass galaxy distribution is a key diagnostic for galaxy evolution. Massive compact galaxies are potential surviving relics of a high-redshift phase of star formation. Some of these could be nearly unresolved in Sloan Digital Sky Survey (SDSS) imaging and thus not included in galaxy samples. To overcome this, a sample was selected from the…
Connecting Galactic Outflows and Star Formation: Inferences from Hα Maps and Absorption-line Spectroscopy at 1 ≲ z ≲ 1.5
Martin, Crystal L.; Erb, Dawn K.; Prusinski, Nikolaus Z.
We investigate the connection between galactic outflows and star formation using two independent data sets covering a sample of 22 galaxies between 1 ≲ z ≲ 1.5. The Hubble Space Telescope WFC3/G141 grism provides low spectral resolution, high spatial resolution spectroscopy yielding Hα emission-line maps from which we measure the spatial extent an…
The RS CVn-type Star GT Mus Shows Most Energetic X-Ray Flares Throughout the 2010s
Hamaguchi, Kenji; Corcoran, Michael F.; Maeda, Yoshitomo +14 more
We report that the RS CVn-type star GT Mus (HR 4492, HD 101379+HD 101380) was the most active star in the X-ray sky in the last decade in terms of the scale of recurrent energetic flares. We detected 11 flares from GT Mus in 8 yr of observations with the Monitor of All-sky X-ray Image (MAXI) from 2009 August to 2017 August. The detected flare peak…
Galactic open cluster Cepheids - a census based on Gaia EDR3
Chen, Xiaodian; Zhou, Xiaoyue
In the Gaia era, the membership analysis and parameter determination of open clusters (OCs) are more accurate. We performed a census of OC's classical Cepheids based on Gaia Early Data Release 3 (EDR3) and obtained a sample of 33 OC Cepheids fulfilling the constraints of the spatial position, proper motion, parallax, and evolution state. 13 of 33 …