| Description |
We request 59.8 hours of Herschel time to observe 20 normal
star-forming galaxies in the [CII] 158 micron and [OI] 63 micron lines.
These galaxies lie at high redshift (1<z<3). They are highly magnified
by gravitational lensing, but have modest star formation rates.
Therefore they represent our best chance of studying star formation
and the interstellar medium in typical, common galaxies at this epoch.
Redshift 1 to 3 spans the peak of both star formation activity and black
hole accretion in active galactic nuclei-- a period that was crucial in
shaping our modern universe. Most of this redshift range is
inaccesible to ground-based observations of [CII], [OI], or both.
Herschel offers the unique opportunity to study both lines with high
sensitivity throughout this epoch (using HIFI for [CII] and PACS for [OI]).
These two lines are the main cooling lines of the atomic medium.
By measuring their fluxes, we will measure (1) the cooling efficiency of
gas, (2) gas densities and temperatures near starforming regions,
and (3) gas pressures, which are important to drive the winds
that provide feedback to starformation processes.
By combining the proposed observations with existing multiwavelength
data on these objects, we will obtain as complete a picture of
galaxy-scale star formation and ISM physical conditions at high redshifts
as we have at z=0. Then perhaps we can understand why star formation
and AGN activity peaked at this epoch.
In Herschel cycle OT1, 49 high redshift IR luminous galaxies were
approved for spectroscopy, but only two so-called normal galaxies
were included. This is an imbalance that should be corrected,
to balance Herschel.s legacy. |
| Publication |
Herschel Extreme Lensing Line Observations: Dynamics of Two Strongly Lensed Star-forming Galaxies near Redshift z = 2 . Rhoads James E. et al. . The Astrophysical Journal, Volume 787, Issue 1, article id. 8, 7 pp. (2014). . 787 . 10.1088\/0004-637X\/787\/1\/8 . 2014ApJ...787....8R ,
Herschel Extreme Lensing Line Observations: [CII] Variations in Galaxies at Redshifts z=1-3 . Malhotra Sangeeta et al. . The Astrophysical Journal, Volume 835, Issue 1, article id. 110, 9 pp. (2017). . 835 . 10.3847\/1538-4357\/835\/1\/110 . 2017ApJ...835..110M ,
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