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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Mapping low- and high-density clouds in astrophysical nebulae by imaging forbidden line emission

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Steiner, J. E. [1] ; Menezes, R. B. [1] ; Ricci, T. V. [1] ; Oliveira, A. S. [2]
Total Authors: 4
[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508900 Sao Paulo - Brazil
[2] Univ Vale Paraiba, IP & D, BR-12244000 Sao Jose Dos Campos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Monthly Notices of the Royal Astronomical Society; v. 396, n. 2, p. 788-793, June 2009.
Field of knowledge: Physical Sciences and Mathematics - Astronomy
Web of Science Citations: 6

Emission line ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with emission lines related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform images taken from density-sensitive forbidden lines into images of emission from high- and low-density clouds by applying a transformation matrix. In order to achieve this, images of the pairs of density-sensitive lines as well as the adjacent continuum have to be observed and combined. We have computed the critical densities for a series of pairs of lines in the infrared, optical, ultraviolet and X-rays bands, and calculated the pair line intensity ratios in the high- and low-density limit using a four- and five-level atom approximation. In order to illustrate the method, we applied it to Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (GMOS-IFU) data of two galactic nuclei. We conclude that this method provides new information of astrophysical interest, especially for mapping low- and high-density clouds; for this reason, we call it 'the ld/hd imaging method'. (AU)

FAPESP's process: 06/05203-3 - Differentiation of models for LINERs
Grantee:Roberto Bertoldo Menezes
Support type: Scholarships in Brazil - Master