The Star Formation Newsletter

s of recently accepted papers Formal Results Regarding Metric-Space Techniques for the Study of Astrophysical Maps Fred C. Adams and Jennifer J. Wiseman Physics Department, University of Michigan, Ann Arbor, MI 48109, USA Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA We extend a newly developed formal system for the description of astrophysical maps. In this formalism, we consider the difference between maps to be the distance between elements of a pseudometric space (the space of all such maps). This ansatz allows us to measure quantitatively the difference between any two maps and to order the space of all maps. For each physical characteristic of interest, this technique assigns an “output” function to each map; the difference between the maps is then determined from the difference between their corresponding output functions. In this present study, we show that the results of this procedure are invariant under a class of transformations of the maps and the domains of the maps. In addition, we study the propagation of errors (observational uncertainties) through this formalism. We show that the uncertainties in the output functions can be controlled provided that the signal to noise ratios in the original astrophysical maps are sufficiently high. The results of this paper thus increase the effectiveness of this formal system for the description, classification, and analysis of astrophysical maps. Accepted by The Astrophysical Journal Widespread water vapor emission in Orion J. Cernicharo, E. Gonzalez-Alfonso, J. Alcolea, R. Bachiller, D. John Centro Astronómico de Yebes (IGN), Apdo. 148, E-19080 Guadalajara, Spain IRAM, Granada, Spain We have discovered spatially extended emission in the 3(13)-2(20) line of water vapor in Orion. The mapped region is 160” x 240” wide. Many strong narrow features with flux density (115) 10 Jy have been detected around OriA-Irc2. These features appear over a weaker (10 Jy) high velocity plateau whose half power size is 45”, and its total extent is 80” x 80”. Narrow lines with intensities 25200 Jy (i.e. much stronger than the expected contribution from the secondary and error beams) are detected at all observed positions outside the central region. These emission lines are not arising from point sources, and different emission regions are well resolved by our 15” beam. This is the first time that widespread water emission has been found in the interstellar medium. From statistical equilibrium calculations for the physical conditions of the Orion molecular cloud, we conclude that the observed emission is dominantly maser in nature. This is the first observation of spatially extended maser emission resolved by a single-dish telescope. The water abundance is estimated to be larger that 5 x 10−5, which confirms chemistry expectations that water vapor is a substantial component of the gas phase in warm molecular clouds, and one of the most important gas coolants. Accepted by Astrophys. J. Letters