Free–Floating HI Clouds in the M 81 Group
نویسندگان
چکیده
منابع مشابه
Free–Floating HI Clouds in the M 81 Group
Recent VLA observations pointed at dwarf spheroidal (dSph) galaxies in the M81 group reveal a hitherto hidden population of extremely low mass ( ∼ 10 M⊙) HI clouds with no obvious optical counterparts. We have searched 10 fields in the M81 group totalling 2.2 square degree, both targeting known dwarf spheroidal galaxies and blank fields around the central triplet. Our observations show that the...
متن کاملObservations of Individual Giant Molecular Clouds in M 81
Received ; accepted – 2 – ABSTRACT We present 12 CO J=1-0 observations from the Caltech Millimeter Array of a field in the nearby spiral galaxy M81. We detect emission from three features that are the size of large giant molecular clouds (GMCs) in the Milky Way Galaxy and M31, but are larger than any known in M33 or the SMC. The M81 clouds have diameters ∼ 100 pc and molecular masses ∼ 3 × 10 5...
متن کاملIntergalactic Hi Clouds
Neutral intergalactic clouds are so greatly out numbered by galaxies that their integral HI content is negligible in comparison to that contained in optically luminous galaxies. In fact, no HI cloud that is not associated with a galaxy or grouping of galaxies has yet been identified. This points to a causal relationship that relies on gravitational potentials that bind galaxies also being respo...
متن کاملTiny Hi Clouds in the Local Ism
We report deep, high spectral resolution WSRT H I 21cm observations of four high latitude compact radio sources, that have revealed a new population of tiny, discrete clouds in the diffuse ISM, with peak optical depths τ ∼ 0.1−2%, H I column densities of 0.4–8 ×1018 cm−2 and core temperatures of 20–80 K. Imaging detections confirm these low column densities and imply linear core dimensions of a...
متن کاملHi Clouds beyond the Galactic Disk
Recent observations in the 21cm line with the Green Bank Telescope have changed our view of the neutral interstellar medium (ISM) in several ways. The new data show that in the inner parts of the Milky Way the disk-halo interface is composed of many discrete HI clouds. The clouds lie in a layer more than one kpc thick and follow Galactic rotation. Their origin and evolution is unknown. In the o...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2007
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921307013907