+ Visit NASA.gov + Contact NASA   + Home Collection > NASA  Author > Digel, S.  Author > Thaddeus, Patrick  NASA Center > Goddard Space Flight Center  Publication Year > 1991-2000 > 1998  Subject > S-U > Space Radiation  Availability Options > Online > PDF  Item/Media Type > Technical Report  Note: Start a new navigation search by selecting a link above     Previous Record | Next Record + Back to Results   + Printer Friendly Title: Gamma-Ray Observations of the Interstellar Clouds in Cepheus Author(s): Digel, S.; Thaddeus, Patrick Abstract: During the last six months of the period of performance, the diffuse gamma-ray emission from the Monoceros region was reanalyzed and one of the important conclusions was revised as a result. The reanalysis incorporated newly-available data from recent EGRET viewing periods and revealed a previously-uncataloged gamma-ray point source near the plane in Monoceros. The effect of incorporating this source in the diffuse emission model was significant, as its flux was comparable to that from a large interstellar cloud complex in the Perseus arm. In the updated model, a greatly reduced gamma-ray emissivity was found in the Perseus arm. This finding alters the previous conclusion that we had found evidence for an enhanced emissivity in the arm, which had supported the hypothesis that cosmic rays are coupled to the interstellar medium on the scale of spiral arms. Our updated findings are consistent with our previous results for the emissivity toward the Cepheus region (Digel et al. 1996), where a monotonic gradient of emissivity in the outer Galaxy was found. The updated analysis of Monoceros was presented at the June, 1998 meeting of the American Astronomical Society, and a journal publication should be ready for submission soon. NASA Center: Goddard Space Flight Center Publication Date: Sep. 17, 1998 Document Source: CASI Online Source: View PDF File Document ID: 19980237336 Publication Information: Number of Pages = 6 Contract-Grant-Task Number: NAG5-2823 Price Code: A02 Keywords: INTERSTELLAR MATTER; MOLECULAR CLOUDS; GAMMA RAY OBSERVATORY; GAMMA RAYS; COSMIC RAYS; POINT SOURCES; HYPOTHESES; GAMMA RAY TELESCOPES; ASTRONOMY; EMISSIVITY; Accessibility: Unclassified; No Copyright; Unlimited; Publicly available; Final Report Updated/Added to NTRS: 2008-06-02 + Back to Top + Sponsored by the NASA Scientific and Technical    Information Program + 2004 Vision for Space Exploration + Freedom of Information Act + NASA Web Privacy Policy and Important Notices + NASA Disclaimers, Copyright Notice,    and Terms and Conditions of Use NASA Official: Calvin Mackey Page Curator: NASA Center for AeroSpace Information (help@sti.nasa.gov) Last Updated: July 5, 2007