Search Publications
Testing Physical Scenarios for the Reflection Features of Type-1 AGNs using XMM-Newton and NuSTAR Simultaneous Observations
González-Martín, Omaira; Masegosa, Josefa; Victoria-Ceballos, César Ivan +3 more
Above ~3 keV, the X-ray spectrum of active galactic nuclei (AGNs) is characterized by the intrinsic continuum and Compton reflection features. For type-1 AGNs, several regions may contribute to the reflection. To investigate the nature of the reflecting medium, we perform a systematic analysis of the reflector using XMM-Newton and Nuclear Spectros…
Speed and Acceleration of Coronal Mass Ejections Associated with Sustained Gamma-Ray Emission Events Observed by Fermi/LAT
Gopalswamy, Nat; Akiyama, Sachiko; Yashiro, Seiji +2 more
The sustained gamma-ray emission (SGRE) from the Sun is a prolonged enhancement of >100 MeV gamma-ray emission that extends beyond the flare impulsive phase. The origin of the >300 MeV protons resulting in SGRE is debated, with both flares and shocks driven by coronal mass ejections (CMEs) being the suggested sites of proton acceleration. We…
Structure of the W3A Low-density Foreground Region
Seo, Youngmin; Goldsmith, Paul. F.; Stutzki, Jürgen +5 more
We present analysis of [O I] 63 µm and CO J = 5 - 4 and 8 - 7 multiposition data in the W3A region and use it to develop a model for the extended low-density foreground gas that produces absorption features in the [O I] and J = 5 - 4 CO lines. We employ the extinction to the exciting stars of the background H II region to constrain the total…
The Low-temperature Corona in ESO 511-G030 Revealed by NuSTAR and XMM-Newton
Fabian, Andrew C.; Reynolds, Christopher S.; Yu, Zhibo +9 more
We present the results from a coordinated XMM-Newton + NuSTAR observation of the Seyfert 1 galaxy ESO 511-G030. With this joint monitoring program, we conduct a detailed variability and spectral analysis. The source remained in a low flux and very stable state throughout the observation period, although there are slight fluctuations of flux over l…
New Resonance Scattering Model in AtomDB: Application to Line Suppression in Galaxy Clusters and Elliptical Galaxies
Raymond, John; Smith, Randall; Chakraborty, Priyanka +2 more
In this paper, we present the simple, one-step, self-consistent, and fast resonance scattering model rsapec based on the AtomDB database. This model can be used as an alternative to the commonly used APEC model for fitting X-ray spectra with optically thick lines. The current model is intended, in general, for verifying the presence of the effect …
The Photodissociation and Ionization Fronts in M17-SW Localized with FIFI-LS on Board SOFIA
Fadda, Dario; Looney, Leslie W.; Tielens, Alexander G. G. M. +5 more
To understand star formation rates, studying feedback mechanisms that regulate star formation is necessary. The radiation emitted by nascent massive stars play a significant role in feedback by photodissociating and ionizing their parental molecular clouds. To gain a detailed picture of the physical processes, we mapped the photodissociation regio…
Disk Dissipation, Giant Planet Formation, and Star Formation Rate Fluctuations in the 3 Myr History of Gould's Belt
Liu, Tie; He, Jinhua; Ge, Jixing +3 more
Although episodic star formation (SF) has been suggested for nearby SF regions, a panoramic view of the recent episodic SF history in the solar neighborhood is still missing. By uniformly constraining the slope α of infrared spectral energy distributions (SEDs) of young stellar objects (YSOs) in the 13 largest Gould's Belt (GB) protoclusters surve…
Recovering Thermodynamics from Spectral Profiles Observed by IRIS. (II). Improved Calculation of the Uncertainties Based on Monte Carlo Experiments
De Pontieu, Bart; Sainz Dalda, Alberto
Observations by the Interface Region Imaging Spectrograph (IRIS) of the Mg II h & k spectral lines have provided a new diagnostic window toward knowledge of the complex physical conditions in the solar chromosphere. Theoretical efforts focused on understanding the behavior of these lines have allowed us to obtain a better and more accurate vis…
Extreme Rarefaction of Solar Wind: A Study on Origin and Characteristics Using Ulysses Observations
Hajra, Rajkumar; Tsurutani, Bruce T.; Lu, Quanming +5 more
From the Ulysses observation of the solar wind between the heliocentric distance r h of ~1.0 and ~5.4 au during 1990-2009, we identified 53 intervals when the solar wind exhibited extreme rarefaction, ~2 orders of magnitude decreases in the solar wind proton density N p from their ambient values. These extremely low-densi…
Energy-releasing Process for the 2013 May 13 X1.7 Limb Flare: A Continued Study
Li, Dong; Ji, Haisheng; Huang, Yu +3 more
In this paper, we reanalyze the X1.7 class limb flare that occurred on 2013 May 13 (SOL2013-05-13T01:56 UT), concentrating on the energy-releasing process using microwave observations mainly made by Nobeyama and X-ray observations made by RHESSI. The analysis was carried out in the context of EUV observations made by the Atmospheric Imaging Assemb…