Search Publications
The Surface Brightness-color Relations Based on Eclipsing Binary Stars: Toward Precision Better than 1% in Angular Diameter Predictions
Gieren, Wolfgang; Pietrzyński, Grzegorz; Maxted, Pierre F. L. +7 more
In this study we investigate the calibration of surface brightness-color (SBC) relations based solely on eclipsing binary stars. We selected a sample of 35 detached eclipsing binaries with trigonometric parallaxes from Gaia DR1 or Hipparcos whose absolute dimensions are known with an accuracy better than 3% and that lie within 0.3 kpc from the Sun…
The Optical/UV Excess of X-Ray-dim Isolated Neutron Stars. I. Bremsstrahlung Emission from a Strangeon Star Atmosphere
Ge, Mingyu; Li, Zhaosheng; Xu, Renxin +4 more
X-ray-dim isolated neutron stars (XDINSs) are characterized by Planckian spectra in X-ray bands, but show optical/ultraviolet (UV) excesses: the factors by which the measured photometry exceeds those extrapolated from X-ray spectra. To solve this problem, a radiative model of bremsstrahlung emission from a plasma atmosphere is established in the r…
The Broadband Spectral Variability of Holmberg IX X-1
Harrison, F. A.; Ptak, A.; Stern, D. +9 more
We present results from four new broadband X-ray observations of the extreme ultraluminous X-ray source Holmberg IX X-1 ({L}{{X}}> {10}40 erg s-1), performed by Suzaku and NuSTAR in coordination. Combined with the archival data, we now have broadband observations of this remarkable source from six separate epoch…
The Lifetimes of Phases in High-mass Star-forming Regions
Battersby, Cara; Bally, John; Svoboda, Brian
High-mass stars form within star clusters from dense, molecular regions (DMRs), but is the process of cluster formation slow and hydrostatic or quick and dynamic? We link the physical properties of high-mass star-forming regions with their evolutionary stage in a systematic way, using Herschel and Spitzer data. In order to produce a robust estimat…
Age Spreads and the Temperature Dependence of Age Estimates in Upper Sco
Herczeg, Gregory J.; Rizzuto, Aaron; Fang, Qiliang
Past estimates for the age of the Upper Sco Association are typically 11-13 Myr for intermediate-mass stars and 4-5 Myr for low-mass stars. In this study, we simulate populations of young stars to investigate whether this apparent dependence of estimated age on spectral type may be explained by the star formation history of the association. Solar …
Toward Understanding the 3D Structure and Evolution of Magnetic Flux Ropes in an Extremely Long Duration Eruptive Flare
Wang, Yuming; Chintzoglou, Georgios; Liu, Rui +2 more
In this work, we analyze the initial eruptive process of an extremely long duration C7.7-class flare that occurred on 2011 June 21. The flare had a 2 hr long rise time in soft X-ray emission, which is much longer than the rise time of most solar flares, including both impulsive and gradual ones. Combining the facts that the flare occurred near the…
Detection of a Substantial Molecular Gas Reservoir in a Brightest Cluster Galaxy at z = 1.7
Muzzin, Adam; Yee, H. K. C.; Cybulski, Ryan +7 more
We report the detection of CO(2-1) emission coincident with the brightest cluster galaxy (BCG) of the high-redshift galaxy cluster SpARCS1049+56, with the Redshift Search Receiver (RSR) on the Large Millimeter Telescope (LMT). We confirm a spectroscopic redshift for the gas of z = 1.7091 ± 0.0004, which is consistent with the systemic redshift of …
Hubble Space Telescope Scattered-light Imaging and Modeling of the Edge-on Protoplanetary Disk ESO-Hα 569
Duchêne, Gaspard; Wolff, Schuyler G.; Perrin, Marshall D. +6 more
We present new Hubble Space Telescope (HST) Advanced Camera for Surveys observations and detailed models for a recently discovered edge-on protoplanetary disk around ESO-Hα 569 (a low-mass T Tauri star in the Cha I star-forming region). Using radiative transfer models, we probe the distribution of the grains and overall shape of the disk (inclinat…
Different Accretion Heating of the Neutron Star Crust during Multiple Outbursts in MAXI J0556-332
Homan, Jeroen; Miller, Jon M.; Fridriksson, Joel K. +12 more
The transient neutron star (NS) low-mass X-ray binary MAXI J0556-332 provides a rare opportunity to study NS crust heating and subsequent cooling for multiple outbursts of the same source. We examine MAXI, Swift, Chandra, and XMM-Newton data of MAXI J0556-332 obtained during and after three accretion outbursts of different durations and brightness…
Cusp-shaped Structure of a Jet Observed By IRIS and SDO
Zhang, Jun; Zhang, Yuzong
On 2014 August 29, the trigger and evolution of a cusp-shaped jet were captured in detail at 1330 Å by the Interface Region Imaging Spectrograph. At first, two neighboring mini-prominences arose in turn from the low solar atmosphere and collided with a loop-like system over them. The collisions between the loop-like system and the mini-prominences…