Detecting the first objects in the mid-infrared with the Next Generation Space Telescope |
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| Authors: | Benedetta Ciardi † rea Ferrara |
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| Institution: | ;1Universitádi Firenze, Largo Enrico Fermi 5, 50125 Firenze, Italy;2Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy |
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| Abstract: | We calculate the expected mid-infrared (MIR) molecular hydrogen line emission from the first objects in the Universe. As a result of their low masses, the stellar feedback from massive stars is able to blow away their gas content and collect it into a cooling shell where H2 rapidly forms and IR roto-vibrational (as for example the rest-frame 2.12 μm) lines carry away a large fraction (up to 10 per cent) of the explosion energy. The fluxes from these sources are in the range 10?21–10?17 erg s?1 cm?2 . The highest number counts are expected in the 20-μm band, where about 105 sources deg?2 are predicted at the limiting flux of 3×10?18 erg s?1 cm?2. Among the planned observational facilities, we find that the best detection perspectives are offered by the Next Generation Space Telescope ( NGST ), which should be able to reveal about 200 first objects in one hour observation time at its limiting flux in the above band. Therefore, mid-IR instruments appear to represent perfect tools to trace star formation and stellar feedback in the high ( z ?5) redshift Universe. |
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| Keywords: | ISM: molecules galaxies: formation intergalactic medium cosmology: theory |
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