How reliable are galaxies physical parameters estimations for LSST main sequence sample?

The upcoming Large Survey of Space and Time (LSST), conducted by
Vera Rubin Observatory, will produce, over
a 10-year period, multi-petabyte archive of images and catalogs of astrophysical
sources on more than 18000 square degrees of the southern sky.
Reaching magnitude
depth of ∼26.5 (AB) in the six bands ugrizy, LSST data will be useful
to perform a wide variety of high precision statistical studies,
allowing to obtain
more accurate measurements of astrophysical quantities. I will present
studies based
on simulated LSST observations of real galaxies in the ELAIS-N1 and COSMOS
fields of the Herschel Extragalactic Legacy Project (HELP) survey.
Spectral Energy
Distributions (SEDs) were fitted to the real and simulated photometric
measurements
of 65,889 galaxies in the redshift range 0 < z < 2.5, using the latest release
of a galaxy SED fitting code CIGALE. We compare main galaxy physical parameters,
such as star formation rate (SFR), stellar mass and dust luminosity
obtained from
real data using ultraviolet and
infrared observations
to the same parameters obtained from the simulated optical LSST measurements only.
We conclude there is a possible overestimation of SFR, dust luminosity and
dust mass if they are calculated with LSST photometric measurements only.
This overestimation is found to depend on redshift, diminishing up to z = 2.5.
The least sensitive parameter is the stellar mass which was found to
be reliably estimated
even if based only on the optical bands.


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