at 65 pc, mbm-12 is the nearest known molecular cloud. located far from sources of fuv radiation, it provides an ideal laboratory to study translucent interstellar gas. mbm-12 has been extensively mapped in (13)co(1->0) and 14 molecular cores have been identified in the complex. deduced molecular hydrogen densities range from 10e+3 to 10e+4 cm-3 and excitation temperatures are about 10 k. mbm-12 is thus a translucent cloud: densities and temperatures for the cores are typical of dark clouds, while visual extinctions (av is about 2 mag) are typical of diffuse clouds. because of the former property, molecules are able to form in abundance in translucent clouds. however, since av is low, the ambient radiation field plays an important role in their chemistry. mbm-12 cores have visual extinctions such that h2 -> hi and cii -> c -> co photochemistry is occuring. for mbm-12 most of these species have either already been studied or are currently being investigated. missing from, and vital to, any complete characterization of the physical state of the atomic and molecular interstellar medium of the mbm-12 complex is any direct measurement of ionized carbon. iso lws observations of cii will be used in conjunction with existing ci, co, and hi data to study the properties of the 14 atomic/molecular cores in the mbm-12 complex. iso measurements of cii emission from mbm-12 can provide important constraints on models for photodissociation regions (pdrs) in translucent clouds near weak fuv radiation fields.
Instrument
LWS02
Temporal Coverage
1997-02-24T21:56:14Z/1997-09-02T06:51:48Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
European Space Agency, BANIA et al., 1999, 'PROBING THE STRUCTURE OF THE NEAREST MOLECULAR CLOUD MBM-12', 1.0, European Space Agency, https://doi.org/10.5270/esa-1t492a6
