Search Publications
ALMA observations of lensed Herschel sources: testing the dark matter halo paradigm
Ivison, R. J.; Clements, D. L.; Cooray, A. +23 more
With the advent of wide-area submillimetre surveys, a large number of high-redshift gravitationally lensed dusty star-forming galaxies have been revealed. Because of the simplicity of the selection criteria for candidate lensed sources in such surveys, identified as those with S500 µm > 100 mJy, uncertainties associated with th…
Deep Hubble Space Telescope Imaging of Globular Clusters toward the Galactic Bulge: Observations, Data Reduction, and Color-magnitude Diagrams
Cohen, Roger E.; Sarajedini, Ata; Hempel, Maren +5 more
The Galactic globular clusters (GGCs) located toward the Galactic bulge have generally been excluded from large-scale photometric GGC surveys due to severe total and differential extinction. Here we present an overview of a Hubble Space Telescope (HST) program designed to obtain deep, high spatial resolution multiband imaging of 16 poorly studied …
A Bayesian analysis of inflationary primordial spectrum models using Planck data
Benetti, Micol; Alcaniz, Jailson; Santos da Costa, Simony
The current available Cosmic Microwave Background (CMB) data show an anomalously low value of the CMB temperature fluctuations at large angular scales (l < 40). This lack of power is not explained by the minimal ΛCDM model, and one of the possible mechanisms explored in the literature to address this problem is the presence of features in the p…
Unidentified quasars among stationary objects from Gaia DR2
Geier, S.; Fynbo, J. P. U.; Christensen, L. +5 more
Here we apply a technique selecting quasar candidates purely as sources with zero proper motions in the Gaia data release 2 (DR2). We demonstrate that this approach is highly efficient toward high Galactic latitudes with ≲25% contamination from stellar sources. Such a selection technique offers very pure sample completeness, since all cosmological…
Two Solar Tornadoes Observed with the Interface Region Imaging Spectrograph
Chen, Yajie; Tian, Hui; Zhang, Jingwen +4 more
The barbs or legs of some prominences show an apparent motion of rotation, which are often termed solar tornadoes. It is under debate whether the apparent motion is a real rotating motion, or caused by oscillations or counter-streaming flows. We present analysis results from spectroscopic observations of two tornadoes by the Interface Region Imagi…
A new mechanical stellar wind feedback model for the Rosette Nebula
Wright, N. J.; Pittard, J. M.; Wareing, C. J. +1 more
The famous Rosette Nebula has an evacuated central cavity formed from the stellar winds ejected from the 2-6 Myr old codistant and comoving central star cluster NGC 2244. However, with upper age estimates of less than 110 000 yr, the central cavity is too young compared to NGC 2244 and existing models do not reproduce its properties. A new proper …
The 7-year MAXI/GSC X-Ray Source Catalog in the High Galactic Latitude Sky (3MAXI)
Sakamoto, T.; Mihara, T.; Sugizaki, M. +28 more
We present the third MAXI/GSC catalog in the high Galactic latitude sky (| b| > 10^\circ ) based on the 7-year data from 2009 August 13 to 2016 July 31, complementary to that in the low Galactic latitude sky (| b| < 10^\circ ) (Hori et al. 2018). We compile 682 sources detected at significances of s D,4-10 keV ≥ 6.5 in the 4-10 ke…
Localized Quasi-periodic Fluctuations in C II, Si IV, and Fe XXI Emission during Chromospheric Evaporation in a Flare Ribbon Observed by IRIS on 2017 September 9
Brosius, Jeffrey W.; Inglis, Andrew R.
We investigate the onset of a GOES M3.7 flare on 2017 September 9 with rapid-cadence (9.4 s) UV stare spectra obtained with IRIS in five 1″ slit segments. Our analysis is based primarily on integrated intensities and Doppler velocities of C II λ1334.5 (T ≈ 2.5 × 104 K), Si IV λ1402.7 (7.9 × 104 K), and Fe XXI λ1354.1 (1.1 × 1…
A new X-ray look into four old pulsars
Mereghetti, Sandro; Rigoselli, Michela
We report on the X-ray properties of four rotation-powered pulsars with characteristic ages in the range 0.3-5 Myr, derived from the analysis of XMM-Newton archival observations. We found convincing evidence of thermal emission only in the phase-averaged spectrum of PSR B0114+58, which is well fitted by a blackbody with temperature kT = 0.17 ± 0.0…
Statistical Analysis on XMM-Newton X-Ray Flares of Mrk 421: Distributions of Peak Flux and Flaring Time Duration
Wang, Jiancheng; Zhang, Pengfei; Zhang, Li +3 more
The energy dissipation mechanism in blazar jet is unknown. Blazar flares could provide insights into this problem. Here we report statistical results of XMM-Newton observations of X-ray flares in Mrk 421. We analyze all public XMM-Newton X-ray observations for Mrk 421, and construct the light curves. Through fitting the light curves, we obtain the…