Mapping Extended Circumgalactic Lyα
Nebulae Around Quasars With J-PAS

Speaker : Rahna Payyasseri Thanduparackal
Centro de Estudios de Física del Cosmos
de Aragón (CEFCA, Teruel, Spain)

Abstract :

Circum-Galactic Medium (CGM) is the gas surrounding galaxies outside
their disks and inside their virial radii. Lyman-alpha (Lyα) emission is one of
the most important spectral features for probing the CGM at high redshifts,
providing crucial insights into the formation and evolution of galaxies and
their environments in the early Universe. This emission can trace outflows,
inflows, and other processes that are key to understanding how galaxies
interact with their surroundings. However, the origin of Lyα emission around
quasars still under debate, particularly in terms of whether the emission
arises primarily from photoionized gas, from cooling gas in the CGM, or
from processes related to quasar-driven outflows. These different scenarios
have profound implications for our understanding of galaxy formation and
evolution, as they can shed light on feedback mechanisms, gas accretion,
and the impact of quasars on their host galaxies.
In this talk, I will present a study of extended Lyα emission around
quasars at z>2 utilizing the capabilities of the Javalambre Physics of the
Accelerating Universe Astrophysical Survey (J-PAS) with its 54 optical
narrow-band filters over thousands of degrees. I will highlight our recent
discovery of a massive Lyα nebula using J-PAS early data release,
demonstrating the unique ability of J-PAS’s multi-band photometry to detect
faint, extended structures, providing new perspectives on the dynamic
relationship between quasars and their environments at high redshift.