Published November 2012 | Version v1
Journal article

Do the Herschel cold clouds in the Galactic halo embody its dark matter?

  • 1. Institute for Theoretical Physics, University of Amsterdam, Science Park 904, PO Box 94485, 1090-GL Amsterdam (Netherlands)

Description

Recent Herschel/SPIRE (Spectral and Photometric Imaging Receiver) maps of the Small and Large Magellanic Clouds (SMC, LMC) exhibit, in each, thousands of clouds. Observed at 250 μm, they must be cold, T ∼ 15 K, hence the name 'Herschel cold clouds' (HCCs). From the observed rotational velocity profile of the Galaxy and the assumption of spherical symmetry, its mass density is modeled in a form close to that of an isothermal sphere. If the HCCs constitute a certain fraction of it, their angular size distribution has a specified shape. A fit to the data deduced from the SMC/LMC maps supports this and yields 1.7 pc for their average radius. There are so many HCCs that they will make up all the missing Halo mass density if there is spherical symmetry and their average mass is of the order of 10 000M⊙. This compares with the Jeans mass of about 40 000M⊙ and puts forward that the HCCs are, in fact, Jeans clusters, constituting all the Galactic dark matter and many of its missing baryons, a conclusion deduced before from a different field of the sky (Nieuwenhuizen et al 2011 J. Cosmol. 15 6017-29). A preliminary analysis of the intensities yields that the Jeans clusters themselves may consist of some billion MACHOs of a few dozen Earth masses. With a size of dozens of solar radii, they would mostly not lens, but cause occultation of stars in the LMC, SMC and toward the Galactic center, and may thus have been overlooked in microlensing.

Availability note (English)

Available from http://dx.doi.org/10.1088/0031-8949/2012/T151/014085

Additional details

Publishing Information

Journal Title
Physica Scripta (Online)
Journal Volume
2012
Journal Issue
T151
Journal Page Range
[9 p.]
ISSN
1402-4896

Conference

Title
Conference on frontiers of quantum and mesoscopic thermophysics
Acronym
FQMT'11
Dates
25-30 Jul 2011
Place
Prague (Czech Republic)

INIS

Country of Publication
United Kingdom
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
44040536
Subject category
S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
Resource subtype / Literary indicator
Conference
Descriptors DEI
BARYONS; COMPARATIVE EVALUATIONS; DENSITY; DISTRIBUTION; LENSES; MAGELLANIC CLOUDS; MASS; NONLUMINOUS MATTER; SPHERICAL CONFIGURATION; STARS; SYMMETRY; T-15 TOKAMAK
Descriptors DEC
CLOSED PLASMA DEVICES; CONFIGURATION; ELEMENTARY PARTICLES; EVALUATION; FERMIONS; GALAXIES; HADRONS; MATTER; PHYSICAL PROPERTIES; THERMONUCLEAR DEVICES; TOKAMAK DEVICES