Butt, Yousaf, Porter, Troy, Katz, Boaz, Waxman, Eli
For more than fifty years, it has been believed that cosmic ray (CR) nuclei are accelerated to high energies in the rapidly expanding shockwaves created by powerful supernova explosions. Yet...
I comment on the -- apparent -- diffuse X-ray emission reported by Horns et al. in their XMM observations of TeV J2032+4130
INTEGRAL/XMM views on the MeV source GRO J1411-64 (2007)
Torres, Diego F., Zhang, Shu, Reimer, Olaf, Barcons, Xavier, Corral, Amalia, Bosch-Ramon, ValentÃ, ...
INTEGRAL/XMM views on the MeV source GRO J1411-64 (2006)
Torres, Diego F., Zhang, Shu, Reimer, Olaf, Barcons, Xavier, Corral, Amalia, Bosch-Ramon, ValentÃ, ...
The COMPTEL unidentified source GRO J 1411-64 was observed by INTEGRAL and XMM-Newton in 2005. The Circinus Galaxy is the only source detected within the 4$\sigma$ location error of GRO J1411-64, but...
INTEGRAL and XMM-Newton observations towards the unidentified MeV source GRO J1411-64 (2006)
Torres, Diego F., Zhang, Shu, Reimer, Olaf, Barcons, Xavier, Corral, Amalia, Bosch-Ramon, Valenti, ...
The COMPTEL unidentified source GRO J1411-64 was observed by INTEGRAL, and its central part, also by XMM-Newton. The data analysis shows no hint for new detections at hard X-rays. The upper limits in...
Microquasar Jet Irradiation of the Proto-Solar Nebula? (2006)
We explore the possibility that a now-extinct microquasar may have irradiated the proto-solar neighborhood, causing the 'anomalously' high local 11B/10B isotopic ratio. Given the population and...
Deeper Chandra Follow-up of Cygnus TeV Source Perpetuates Mystery (2005)
Butt, Yousaf, Drake, Jeremy, Benaglia, Paula, Combi, Jorge, Dame, Thomas, Miniati, Francesco, ...
A 50 ksec Chandra observation of the unidentified TeV source in Cygnus reported by the HEGRA collaboration reveals no obvious diffuse X-ray counterpart. However, 240 Pointlike X-ray sources are...
Cosmic Ray Acceleration by Stellar Associations? The Case of Cygnus OB2 (2003)
Butt, Yousaf, Benaglia, Paula, Combi, Jorge, Corcoran, Michael, Dame, Thomas, Drake, Jeremy, ...
The origins of all extra-solar cosmic rays -- both the ultra high-energy and lower energy Galactic variety -- remain unclear. It has been argued that the large scale shocks and turbulence induced by...
CHANDRA/VLA Follow-up of TeV J2032+4131, the Only Unidentified TeV Gamma-ray Source (2003)
Butt, Yousaf, Benaglia, Paula, Combi, Jorge, Corcoran, Michael, Dame, Thomas, Drake, Jeremy, ...
The HEGRA Cherenkov telescope array group recently reported a steady and extended unidentified TeV gamma-ray source lying at the outskirts of Cygnus OB2. This is the most massive stellar association...
Drake, Jeremy J., Wagner, R. Mark, Starrfield, Sumner, Butt, Yousaf, Krautter, Joachim, Bond, H. E., ...
V1494 Aql (Nova Aql 1999 No. 2) was discovered on 2 December 1999. We obtained Chandra ACIS-I spectra on 15 April and 7 June 2000 which appear to show only emission lines. Our third observation, on 6...
Is The Enigmatic Source 3EG J1828+0142 a Galactic Microblazar ? (2002)
Butt, Yousaf, Torres, Diego, Romero, Gustavo, Paredes, Josep M., Ribo, Marc, Marti, Josep, ...
The unidentified EGRET source 3EG J1828+0142, located at (l,b) ~ (31.9,5.8) (Hartman et al. 1999), is particularly enigmatic since it displays very high variability over timescales of months (Torres...