24 research outputs found
The galactic census of high- and medium-mass protostars - I. Catalogs and first results from Mopra HCO+ maps
The Census of High- and Medium-mass Protostars (CHaMP) is the first
large-scale, unbiased, uniform mapping survey at sub-parsec scale resolution of
90 GHz line emission from massive molecular clumps in the Milky Way. We present
the first Mopra (ATNF) maps of the CHaMP survey region (300{\deg}>l>280{\deg})
in the HCO+ J=1-0 line, which is usually thought to trace gas at densities up
to 10^11 m-3. In this paper we introduce the survey and its strategy, describe
the observational and data reduction procedures, and give a complete catalogue
of moment maps of the HCO+ J=1-0 emission from the ensemble of 301 massive
molecular clumps. From these maps we also derive the physical parameters of the
clumps, using standard molecular spectral-line analysis techniques. This
analysis yields the following range of properties: integrated line intensity
1-30 K km s-1, peak line brightness 1-7 K, linewidth 1-10 km s-1, integrated
line luminosity 0.5-200 K km s-1 pc^2, FWHM size 0.2-2.5 pc, mean projected
axial ratio 2, optical depth 0.08-2, total surface density 30-3000 M{\sun}
pc-2, number density 0.2-30 x 10^9 m-3, mass 15-8000 M{\sun}, virial parameter
1-55, and total gas pressure 0.3-700 pPa. We find that the CHaMP clumps do not
obey a Larson-type size-linewidth relation. Among the clumps, there exists a
large population of subthermally excited, weakly-emitting (but easily
detectable) dense molecular clumps, confirming the prediction of Narayanan et
al. (2008). These weakly-emitting clumps comprise 95% of all massive clumps by
number, and 87% of the molecular mass, in this portion of the Galaxy; their
properties are distinct from the brighter massive star-forming regions that are
more typically studied. If the clumps evolve by slow contraction, the 95% of
fainter clumps may represent a long-lived stage of pressure-confined,
gravitationally stable massive clump evolution, while the CHaMP ... (abridged)Comment: Submitted to ApJ; edited to referee's comments. 98 pages, 81 figures.
For more information, see http://www.astro.ufl.edu/cham
Creative Self-Efficacy: An Exploration of Its Antecedents, Consequences, and Applied Implications
Protective faith? The role of religiosity in the stressor-strain relationship in helping professions
Diversity-related psychological contract breach and employee work behavior: insights from intergroup emotions theory
No Place for a Woman: Evidence for Gender Bias in Evaluations of Presidential Candidates
Women entrepreneurs in Saudi Arabia: Creative responses to gendered opportunities
Female entrepreneurs in the Kingdom of Saudi Arabia (KSA) experience barriers to their action which require creative strategies to navigate. Despite regulatory efforts to advance female entrepreneurial ventures, sociocultural ascriptions remain and these can be detrimental to women’s business experiences. This chapter explores the exogenous and endogenous circumstances integral to establishing a new venture in Saudi Arabia and the hindrances these can pose to female entrepreneurship. Barriers are identified that frame female entrepreneurial action and their creative responses are highlighted to demonstrate how they can play a crucial role in formulating women’s entrepreneurial identities and their entrepreneurial action. A conceptual framework for future research is outlined that seeks to understand these creative responses