Search Publications
Deep observations of CO line emission from star-forming galaxies in a cluster candidate at z=1.5
Finoguenov, A.; Berta, S.; Magnelli, B. +20 more
We report results from a deep Jansky Very Large Array (JVLA) search for 12CO J = 1-0 line emission from galaxies in a candidate galaxy cluster at z ∼ 1.55 in the COSMOS field. We target four galaxies with optical spectroscopic redshifts in the range z = 1.47-1.59, consistent with the likely redshift for the candidate galaxy cluster. Two…
Hubble Space Telescope Observations of the HD 202628 Debris Disk
Krist, John E.; Stapelfeldt, Karl R.; Plavchan, Peter +1 more
A ring-shaped debris disk around the G2V star HD 202628 (d = 24.4 pc) was imaged in scattered light at visible wavelengths using the coronagraphic mode of the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. The ring is inclined by ~64° from face-on, based on the apparent major/minor axis ratio, with the major axis aligned along…
Multiwavelength Observations of V2775 Ori, an Outbursting Protostar in L 1641: Exploring the Edge of the FU Orionis Regime
Henning, Thomas; Manoj, P.; Kounkel, Marina +9 more
Individual outbursting young stars are important laboratories for studying the physics of episodic accretion and the extent to which this phenomenon can explain the luminosity distribution of protostars. We present new and archival data for V2775 Ori (HOPS 223), a protostar in the L 1641 region of the Orion molecular clouds that was discovered by …
The Solar Wind Energy Flux
Issautier, K.; Meyer-Vernet, N.; Le Chat, G.
The solar-wind energy flux measured near the Ecliptic is known to be independent of the solar-wind speed. Using plasma data from Helios, Ulysses, and Wind covering a large range of latitudes and time, we show that the solar-wind energy flux is independent of the solar-wind speed and latitude within 10 %, and that this quantity varies weakly over t…
What Are Special About Ground-Level Events?. Flares, CMEs, Active Regions and Magnetic Field Connection
Liu, Y.; Nitta, N. V.; Nightingale, R. W. +1 more
Ground level events (GLEs) occupy the high-energy end of gradual solar energetic particle (SEP) events. They are associated with coronal mass ejections (CMEs) and solar flares, but we still do not clearly understand the special conditions that produce these rare events. During Solar Cycle 23, a total of 16 GLEs were registered, by ground-based neu…
The X-ray reflector in NGC 4945: a time- and space-resolved portrait
Bianchi, S.; Elvis, M.; Fabbiano, G. +5 more
We present a time, spectral and imaging analysis of the X-ray reflector in NGC 4945, which reveals its geometrical and physical structure with unprecedented detail. NGC 4945 hosts one of the brightest AGN in the sky above 10 keV, but it is only visible through its reflected/scattered emission below 10 keV, due to absorption by a column density of …
The XMM-Newton survey of the Small Magellanic Cloud
Pietsch, W.; Haberl, F.; Hatzidimitriou, D. +13 more
Context. Although numerous archival XMM-Newton observations existed towards the Small Magellanic Cloud (SMC) before 2009, only a fraction of the whole galaxy had been covered.
Aims: Between May 2009 and March 2010, we carried out an XMM-Newton survey of the SMC, to ensure a complete coverage of both its bar and wing. Thirty-three observations…
Discovery of multiphase cold accretion in a massive galaxy at z = 0.7
Kacprzak, Glenn G.; Spitler, Lee R.; Steidel, Charles C. +2 more
We present detailed photo+collisional ionization models and kinematic models of the multiphase absorbing gas, detected within the Hubble Space Telescope(HST)/COS, HST/STIS and Keck/HIRES spectra of the background quasar TON 153 at 104 kpc along the projected minor axis of a star-forming spiral galaxy (z = 0.6610). Complementary g'r'i'Ks photometry…
SXP 1062, a young Be X-ray binary pulsar with long spin period. Implications for the neutron star birth spin
Pietsch, W.; Haberl, F.; Filipović, M. D. +2 more
Context. The Small Magellanic Cloud (SMC) is ideally suited to investigating the recent star formation history from X-ray source population studies. It harbours a large number of Be/X-ray binaries (Be stars with an accreting neutron star as companion), and the supernova remnants can be easily resolved with imaging X-ray instruments.
Aims: We …
Approximating the X-ray spectrum emitted from astrophysical charge exchange
Smith, R. K.; Foster, A. R.; Brickhouse, N. S.
Charge exchange (CX), both onto ions in the solar wind and potentially in other astrophysical contexts, can create X-ray emission lines largely indistinguishable from those created in collisional or photoionized plasmas. The prime distinguishing characteristic is in the distinctly different line ratios generated by the CX process. A complete astro…