Search Publications
Adaptive Grid Lens Modeling of the Cosmic Horseshoe Using Hubble Space Telescope Imaging
Cui, Wei; Li, Guoliang; Wiesner, Matthew P. +3 more
The Cosmic Horseshoe gravitational lensing system is an extraordinary example of strong gravitational lensing both due to the nearly complete Einstein ring formed in this system and due to the star-forming nature of the lensed z = 2.38 Lyman-break galaxy. In this paper, we describe the development of a new lens modeling package and the lens models…
The Gemini/HST Galaxy Cluster Project: Environment Effects on the Stellar Populations in the Lynx Clusters at z = 1.27
Toft, Sune; Jørgensen, Inger; Hunter, Laura C. +4 more
Few detailed investigations of stellar populations in passive galaxies beyond z ≈ 1 are based on deep spectroscopic observations, due to the difficulty in obtaining such data. We present a study of stellar populations, structure, and mass-to-light ratios (M/L) of a large sample of bulge-dominated galaxies in the two z = 1.27 clusters Lynx E and Ly…
Identification of Herbig Ae/Be Stars in the Small Magellanic Cloud
Zijlstra, A. A.; Simon, Joshua D.; Oliveira, Joana M. +12 more
Protoplanetary disks orbiting intermediate-mass stars, Herbig Ae/Be stars, that have formed in a metal-poor environment may evolve differently than their Galactic cousins. A study of the planet-formation process in such an environment requires identification and characterization of a sample of candidates. We have observed several stars in the Smal…
The Role of a Tiny Brightening in a Huge Geoeffective Solar Eruption Leading to the St. Patrick’s Day Storm
Hayashi, Keiji; Inoue, Satoshi; Bamba, Yumi
The largest magnetic storm in solar cycle 24 was caused by a fast coronal mass ejection (CME) that was related to a small C9.1 flare that occurred on 2015 March 15 in solar active region (AR) NOAA 12297. The purpose of this study is to understand the onset mechanism of the geoeffective huge solar eruption. We focused on the C2.4 flare that occurre…
Peculiar Outbursts of an Ultra-luminous Source: Likely Signs of an Aperiodic Disk-wind
Stiele, H.; Kong, A. K. H.
The metal-rich globular cluster RZ 2109 in the massive Virgo elliptical galaxy NGC 4472 (M49) harbors the ultra-luminous X-ray source XMMU 122939.7+075333. Previous studies showed that this source varies between bright and faint phases on timescales of just a few hours. Here, we report the discovery of two peculiar X-ray bursting events that last …
Prospects for Extending the Mass-Metallicity Relation to Low Mass at High Redshift: A Case Study at z ∼ 1
Cameron, Alex J.; Henry, Alaina; Trenti, Michele +5 more
We report J-band MOSFIRE spectroscopy of a low-mass ({log}({M}* /{M}⊙ )={8.62}-0.06+0.10) star-forming galaxy at z = 0.997 showing the detection of [N II] and [S II] alongside a strong Hα line. We derive a gas-phase metallicity of {log}({{O}}/{{H}})={7.99}-0.23+0.13, placing this ob…
Inner Source Pickup Ions from Chondritic Smooth Interplanetary Dust Particles
Möbius, E.; Schwadron, N. A.; Quinn, P. R.
Inner source pickup ions (PUIs) are thought to be produced by the interaction between solar wind ions and interplanetary dust particles (IDPs). The amount of PUIs produced and their velocity distribution depend on the composition, density, porosity, and size of the IDPs. Quinn et al. simulated the production of PUIs from chondritic porous (CP) IDP…
Asymmetric Transport of the Earth’s Polar Outflows by the Interplanetary Magnetic Field
Feng, Xueshang; Huang, Can; Li, Kun +3 more
The polar outflows, as an important plasma source of the Earth’s magnetosphere, usually exhibit significant north-south asymmetries, which can strongly affect the plasma distributions in the magnetotail lobe and perhaps contribute to the substorm triggering. But the mechanism of the asymmetric transport of these outflows is still unclear. In this …
Probing Coronal Magnetic Fields with Sungrazing Comets: H I Lyα from Pickup Ions
Raymond, J. C.; Giordano, S.
Observations of sungrazing comets can be used to probe the solar corona, to study the composition of the comets, and to investigate the plasma processes that govern the interaction between the coronal plasma and cometary gas. UVCS observations of the intensities and line profiles of H I Lyα trace the density, temperature, and outflow speed of the …
Relating the Carriers of λ5797.1 Diffuse Interstellar Band and λ5800 Red Rectangle Band
Adams, Keir; Oka, Takeshi
The emission spectra of the λ5800 Red Rectangle Band (RRB) are simulated at all regions of the Red Rectangle Nebula, utilizing a polar carbon chain model previously developed for the λ5797.1 diffuse interstellar band (DIB) in absorption in the interstellar medium. If high radiative temperatures are assumed, radiative pumping of numerous rotational…