SCIENCE | firspex

FIRSPEX: Science

FIRSPEX is designed to carry out an all-sky spectroscopic survey operating in the Supra-THz (>1 THz) frequency range.

Builds on European heritage in space technology to create a cost effective space mission aiming to push the supra-THz technology forward and deliver, for the first time, unique 3D maps of the infrared sky.

"Decomposing a galaxy" - the most important species:

NII: can be used to estimate the ionized gas contribution to the CII fluxes.

O: present in both atomic and molecular gas; ratios of its transitions can give the optical depth.

CII: a true tracer of the PDR zone if its HII contribution is small; OI/CII " diagnostics of temperature, densities and radiation field of the gas.

C: very correlated with H2 and CO.

CO: traces the amount and distribution of molecular gas at large scale " mass of the galaxy

Probing the Life-Cycle of the ISM in the Universe: the FIRSPEX concept

The ISM in our Galaxy:

Provide a first census of `how much stuff’ is there of atomic, ionic, molecular material

Delineate the transition of atomic to molecular clouds: essential for understanding stellar evolution

Velocity resolved maps will allow us to study gas kinematics and probe turbulence – the missing piece of information for understanding SF

The ISM in nearby galaxies:

Creating 3D surveys of key transitions of [NII], [CI], [CII] and [OI] to obtain the average gas contained within each component (HII, PDR, neutral) for each type of galaxy.

The atomic and molecular distribution can be used to disentangle the different gas components and to trace individual energetic processes within a galaxy (e.g. star formation, X-rays, shocks…)

The ISM in distant galaxies:

Cooling controls cloud collapse and initiate star formation

[CII] is the strongest cooling line in galaxies and can account for 0.1-1% of total FIR originates mostly in PDR

[OIII]88/52, [NII] 122/205 strong coolants in HII regions

[CII] observations with Herschel in local galaxies & ALMA in z>3 galaxies :

FIRSPEX will bridge the gap