Search Publications
The Distance Measurement of NGC 1313 with Cepheids
Wang, Wei; Yoachim, Peter; Liu, Ji-Feng +1 more
We present the detection of Cepheids in the barred spiral galaxy NGC 1313, using the Wide Field and Planetary Camera 2 on the Hubble Space Telescope. Twenty B(F450W) and V(F555W) epochs of observations spanning over three weeks were obtained, on which the profile-fitting photometry of all stars in the monitored field was performed using the packag…
Dissecting the Power Sources of Low-Luminosity Emission-Line Galaxy Nuclei via Comparison of HST-STIS and Ground-Based Spectra
Filippenko, Alexei V.; Ho, Luis C.; Shields, Joseph C. +3 more
Using a sample of ∼100 nearby line-emitting galaxy nuclei, we have built the currently definitive atlas of spectroscopic measurements of Hα and neighboring emission lines at subarcsecond scales. We employ these data in a quantitative comparison of the nebular emission in Hubble Space Telescope (HST) and ground-based apertures, which offer an order…
A Low-mass Main-sequence Star and Accretion Disk in the Very Faint X-Ray Transient M15 X-3
Heinke, C. O.; Cohn, H. N.; Lugger, P. M. +2 more
We present near-simultaneous {\text{}}{Chandra}/Hubble Space Telescope ({\text{}}{HST}) observations of the very faint (Lx < 1036 erg s-1) X-ray transient source M15 X-3, as well as unpublished archival {\text{}}{Chandra} observations of M15 X-3. The {\text{}}{Chandra} observations constrain the luminosity of M1…
Discovery of Massive, Mostly Star Formation Quenched Galaxies with Extremely Large Lyα Equivalent Widths at z ∼ 3
Koekemoer, Anton M.; Tresse, Laurence; Schinnerer, Eva +21 more
We report a discovery of six massive galaxies with both extremely large Lyα equivalent widths (EWs) and evolved stellar populations at z ∼ 3. These MAssive Extremely STrong Lyα emitting Objects (MAESTLOs) have been discovered in our large-volume systematic survey for strong Lyα emitters (LAEs) with 12 optical intermediate-band data taken with Suba…
Measurements of the Sunyaev-Zel'dovich Effect in MACS J0647.7+7015 and MACS J1206.2-0847 at High Angular Resolution with MUSTANG
Mroczkowski, Tony; Umetsu, Keiichi; Nonino, Mario +18 more
We present high resolution (9″) imaging of the Sunyaev-Zel’dovich Effect (SZE) toward two massive galaxy clusters, MACS J0647.7+7015 (z = 0.591) and MACS J1206.2-0847 (z = 0.439). We compare these 90 GHz measurements, taken with the Multiplexed Squid/TES Array at Ninety Gigahertz (MUSTANG ) receiver on the Green Bank Telescope, with generalized Na…
Variable Stars and Stellar Populations in Andromeda XXI. II. Another Merged Galaxy Satellite of M31?
Cignoni, Michele; Marconi, Marcella; Ripepi, Vincenzo +8 more
B and V time-series photometry of the M31 dwarf spheroidal satellite Andromeda XXI (And XXI) was obtained with the Large Binocular Cameras at the Large Binocular Telescope. We have identified 50 variables in And XXI, of which 41 are RR Lyrae stars (37 fundamental-mode—RRab, and 4 first-overtone-RRc, pulsators) and 9 are Anomalous Cepheids (ACs). T…
The Origin of the Hot Gas in the Galactic Halo: Testing Galactic Fountain Models' X-Ray Emission
Henley, David B.; Shelton, Robin L.; Hill, Alex S. +2 more
We test the X-ray emission predictions of galactic fountain models against XMM-Newton measurements of the emission from the Milky Way's hot halo. These measurements are from 110 sight lines, spanning the full range of Galactic longitudes. We find that a magnetohydrodynamical simulation of a supernova-driven interstellar medium, which features a fl…
Cross-correlation of Near- and Far-infrared Background Anisotropies as Traced by Spitzer and Herschel
Gong, Yan; Cooray, Asantha; Mitchell-Wynne, Ketron +3 more
We present the cross-correlation between the far-infrared (far-IR) background fluctuations as measured with the Herschel Space Observatory at 250, 350, and 500 µm and the near-infrared (near-IR) background fluctuations with the Spitzer Space Telescope at 3.6 and 4.5 µm. The cross-correlation between the FIR and NIR background anisotrop…
Evidence for Decay of Turbulence by MHD Shocks in the ISM via CO Emission
Larson, Rebecca L.; Green, Joel D.; Yang, Yao-Lun +1 more
We utilize observations of sub-millimeter rotational transitions of CO from a Herschel Cycle 2 open time program (“COPS”, PI: J. Green) to identify previously predicted turbulent dissipation by magnetohydrodynamic (MHD) shocks in molecular clouds. We find evidence of the shocks expected for dissipation of MHD turbulence in material not associated …
Constraining Very High Mass Population III Stars through He II Emission in Galaxy BDF-521 at z = 7.01
Fan, Xiaohui; Jiang, Linhua; Cai, Zheng +4 more
Numerous theoretical models have long proposed that a strong He II λ1640 emission line is the most prominent and unique feature of massive Population III (Pop III) stars in high-redshift galaxies. The He II λ1640 line strength can constrain the mass and initial mass function (IMF) of Pop III stars. We use F132N narrowband filter on the Hubble Spac…