Search Publications
Properties of Polycyclic Aromatic Hydrocarbons in the Northwest Photon Dominated Region of NGC 7023. III. Quantifying the Traditional Proxy for PAH Charge and Assessing its Role
Boersma, C.; Allamandola, L. J.; Bregman, J.
Polycyclic aromatic hydrocarbon (PAH) emission in the Spitzer/IRS spectral map of the northwest photon dominated region (PDR) in NGC 7023 is analyzed. Here, results from fitting the 5.2-14.5 µm spectrum at each pixel using exclusively PAH spectra from the NASA Ames PAH IR Spectroscopic Database (www.astrochem.org/pahdb/) and observed PAH ban…
The Arches Cluster: Extended Structure and Tidal Radius
Hosek, Matthew W., Jr.; Lu, Jessica R.; Clarkson, William I. +3 more
At a projected distance of ∼26 pc from Sgr A*, the Arches cluster provides insight into star formation in the extreme Galactic center (GC) environment. Despite its importance, many key properties, such as the cluster’s internal structure and orbital history, are not well known. We present an astrometric and photometric study of the outer region of…
O2 Emission toward Orion H2 Peak 1 and the Role of FUV-illuminated C-shocks
Kaufman, Michael J.; Melnick, Gary J.
Molecular oxygen (O2) has been the target of ground-based and space-borne searches for decades. Of the thousands of lines of sight surveyed, only those toward Rho Ophiuchus and Orion H2 Peak 1 have yielded detections of any statistical significance. The detection of the O2 NJ = 33-12
First New Solar Models with OPAS Opacity Tables
Salmon, S.; Turck-Chièze, S.; Le Pennec, M. +4 more
Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However, the particular case of the Sun is still challenging. For about a decade now, the helioseismic sound-speed determination has continued to disagree with the standard solar model (SSM) prediction, question…
Band-9 ALMA Observations of the [N II] 122 µm Line and FIR Continuum in Two High-z galaxies.
Sheth, Kartik; Falgarone, Edith; Nikola, Thomas +4 more
We present Atacama Large Millimeter Array (ALMA) observations of two high-redshift systems (SMMJ02399-0136 at z 1 ∼ 2.8 and the Cloverleaf QSO at z 1 ∼ 2.5) in their rest-frame 122 µm continuum (ν sky ∼ 650 GHz, λ sky ∼ 450 µm) and [N ii] 122 µm line emission. The continuum observations…
Hiding in Plain Sight: Record-breaking Compact Stellar Systems in the Sloan Digital Sky Survey
Janz, Joachim; Forbes, Duncan A.; Romanowsky, Aaron J. +10 more
Motivated by the recent, serendipitous discovery of the densest known galaxy, M60-UCD1, we present two initial findings from a follow-up search, using the Sloan Digital Sky Survey, Subaru/Suprime-Cam, and Hubble Space Telescope imaging, and SOuthern Astrophysical Research (SOAR)/Goodman spectroscopy. The first object discovered, M59-UCD3, has a si…
Characterization of the Inner Knot of the Crab: The Site of the Gamma-Ray Flares?
Weisskopf, Martin C.; Tennant, Allyn; Caraveo, Patrizia +18 more
A particularly intriguing recent result from γ-ray astronomy missions is the detection of powerful flares from the Crab Nebula, which challenges the current understanding of pulsar wind nebulae and acceleration mechanisms. To search for the production site(s) of these flares, we conducted a multi-wavelength observing campaign using Keck, the Hubbl…
Herschel Observations of Extra-ordinary Sources: Analysi sof the HIFI 1.2 THz Wide Spectral Survey toward Orion KL II. Chemical Implications
Favre, C.; Bergin, E. A.; Crockett, N. R. +5 more
We present chemical implications arising from spectral models fit to the Herschel/HIFI spectral survey toward the Orion Kleinmann-Low nebula (Orion KL). We focus our discussion on the eight complex organics detected within the HIFI survey utilizing a novel technique to identify those molecules emitting in the hottest gas. In particular, we find th…
Proper Motions in Terzan 5: Membership of the Multi-iron Subpopulations and First Constraint on the Orbit
Dalessandro, E.; Massari, D.; Rich, R. M. +6 more
By exploiting two sets of high-resolution images obtained with the Hubble Space Telescope Advanced Camera for Surveys/Wide Field Channel over a baseline of ∼10 years, we have measured relative proper motions (PMs) of ∼70,000 stars in the stellar system Terzan 5. The results confirm the membership of the three subpopulations with different iron abu…
A Two-ribbon White-light Flare Associated with a Failed Solar Eruption Observed by ONSET, SDO, and IRIS
Cheng, X.; Ding, M. D.; Chen, P. F. +4 more
Two-ribbon brightenings are one of the most remarkable characteristics of an eruptive solar flare and are often used to predict the occurrence of coronal mass ejections (CMEs). Nevertheless, it was recently called into question whether all two-ribbon flares are eruptive. In this paper, we investigate a two-ribbon-like white-light (WL) flare that i…