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Effects of Solar Active Regions on Meridional Flows
Zhao, Junwei; Kosovichev, Alexander G.; Švanda, Michal
The aim of this Letter is to extend our previous study of the solar-cycle variations of meridional flows and to investigate their latitudinal and longitudinal structure in the subphotospheric layer, especially their variations in magnetic regions. Helioseismology observations indicate that mass flows around active regions are dominated by inflows …
Recent volcano ice interaction and outburst flooding in a Mars polar cap re-entrant
Hovius, Niels; Lea-Cox, Andrew; Turowski, Jens M.
Formation of chasms in the polar ice caps of Mars has been attributed to meltwater outburst floods, but the cause of melting has remained uncertain. In a cap re-entrant enveloping Abalos Colles, west of Casma Boreale in the north polar cap, we have found possible evidence of recent volcano-ice interaction and outburst flooding. In this paper we de…
New active galactic nuclei among the INTEGRAL and SWIFT X-ray sources
Bikmaev, I. F.; Sunyaev, R. A.; Sazonov, S. Yu. +4 more
We present the results of our optical identifications of a set of X-ray sources from the INTEGRAL and SWIFT all-sky surveys. The optical data have been obtained with the 1.5-m Russian-Turkish Telescope (RTT-150). Nine X-ray sources have been identified with active galactic nuclei (AGNs). Two of them are located in the nearby spiral galaxies MCG-01…
The Extended Fe Distribution in the Intracluster Medium and the Implications Regarding AGN Heating
David, Laurence P.; Nulsen, Paul E. J.
We present a systematic analysis of XMM-Newton observations of eight cool-core clusters of galaxies and determine the Fe distribution in the intracluster medium relative to the stellar distribution in the central dominant galaxy (CDG). Our analysis shows that the Fe is significantly more extended than the stellar mass in the CDG in all of the clus…
High-redshift blazar identification for Swift J1656.3-3302
Palazzi, E.; Masetti, N.; Gehrels, N. +9 more
We report on the high-redshift blazar identification of a new gamma-ray source, Swift J1656.3-3302, detected with the BAT imager onboard the Swift satellite and the IBIS instrument on the INTEGRAL satellite. Follow-up optical spectroscopy has allowed us to identify the counterpart as an R∼ 19 mag source that shows broad Lyman-α, Si iv, He ii, C iv…
Helioseismology and the solar cycle
Howe, Rachel
Helioseismic measurements stretching back for about three decades have clearly shown that the acoustic modes are sensitive to solar-cycle changes. 2006 marks the first full 11-year cycle of continuous observations from the Global Oscillation Network Group (GONG), and 10 years of observations with the Michelson Doppler Imager (MDI) aboard the SOHO …
Multi-spacecraft observations of polar coronal plumes
Feng, L.; Wilhelm, K.; Curdt, W. +1 more
Aims:Coronal plumes, along with their structure and rôle in the acceleration of the fast solar wind, are of considerable importance in understanding the physics of the solar atmosphere, in particular, when contrasted with the adjacent plasma, the so-called interplume regions.
Methods: Observations of coronal plumes in a coronal hole were obtai…
Constraining the mass of the GRB 030329 progenitor
Hayes, Matthew; Östlin, Göran; Sollerman, Jesper +2 more
The long-duration gamma-ray burst (GRB) GRB 030329, associated with the supernova (SN) SN 2003dh, occurred inside a star-forming dwarf galaxy at redshift z = 0.1685. The low redshift, and a rich set of archival Hubble Space Telescope (HST) images, makes this GRB well suited for a detailed study of the stellar population in the immediate vicinity o…
A Giant Metrewave Radio Telescope Multifrequency Radio Study of the Isothermal Core of the Poor Galaxy Cluster AWM 4
Raychaudhury, Somak; Clarke, Tracy E.; Mazzotta, Pasquale +7 more
We present a detailed radio morphological study and spectral analysis of the wide-angle tail radio source 4C +24.36 associated with the dominant galaxy in the relaxed galaxy cluster AWM 4. Our study is based on new high-sensitivity GMRT observations at 235, 327, and 610 MHz and on literature and archival data at other frequencies. We find that the…
Independent Emission and Absorption Abundances for Planetary Nebulae
Zhang, Yong; Jenkins, Edward B.; Phillips, Mark +4 more
Emission-line abundances have been uncertain for more than a decade due to unexplained discrepancies in the relative intensities of the forbidden lines and weak permitted recombination lines in PNe and H II regions. The observed intensities of forbidden and recombination lines originating from the same parent ion differ from their theoretical valu…