Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract: We present Ly$\alpha$ and ultraviolet-continuum (UV) luminosity functions
(LFs) of galaxies and active galactic nuclei (AGN) at $z=2.0-3.5$ determined by
the un-targetted optical spectroscopic survey of the Hobby-Eberly Telescope
Dark Energy Experiment (HETDEX). We combine deep Subaru imaging with HETDEX
spectra resulting in $11.4$ deg$^2$ of fiber-spectra sky coverage, obtaining
$18320$ galaxies spectroscopically identified with Ly$\alpha$ emission, $2126$
of which host type 1 AGN showing broad (FWHM$~>1000$ km s$^{-1}$) Ly$\alpha$
emission lines. We derive the Ly$\alpha$ (UV) LF over 2 orders of magnitude
covering bright galaxies and AGN in $\log
L_\mathrm{Ly\alpha}/\mathrm{[erg~s^{-1}]}=43.3-45.5$ ($-27
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract: The GRAVITY instrument has been revolutionary for near-infrared interferometry by pushing sensitivity and precision to previously unknown limits. With the upgrade of GRAVITY and the Very Large Telescope Interferometer (VLTI) in GRAVITY+, these limits will be pushed even further, with vastly improved sky coverage, as well as faint-science and high-contrast capabilities. This upgrade includes the implementation of wide-field off-axis fringe-tracking, new adaptive optics systems on all Unit Telescopes, and laser guide stars in an upgraded facility. GRAVITY+ will open up the sky to the measurement of black hole masses across cosmic time in hundreds of active galactic nuclei, use the faint stars in the Galactic centre to probe General Relativity, and enable the characterisation of dozens of young exoplanets to study their formation, bearing the promise of another scientific revolution to come at the VLTI.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract: We present the first publicly released catalog of sources obtained from the
Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). HETDEX is an integral
field spectroscopic survey designed to measure the Hubble expansion parameter
and angular diameter distance at 1.88
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract: The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is an untargeted spectroscopic survey that aims to measure the expansion rate of the Universe at $z \sim 2.4$ to 1% precision for both $H(z)$ and $D_A(z)$. HETDEX is in the process of mapping in excess of one million Lyman Alpha emitting (LAE) galaxies and a similar number of lower-z galaxies as a tracer of the large-scale structure. The success of the measurement is predicated on the post-observation separation of galaxies with Ly$\alpha$ emission from the lower-$z$ interloping galaxies, primarily [OII], with low contamination and high recovery rates. The Emission Line eXplorer (ELiXer) is the principal classification tool for HETDEX, providing a tunable balance between contamination and completeness as dictated by science needs. By combining multiple selection criteria, ELiXer improves upon the 20 Angstrom rest-frame equivalent width cut commonly used to distinguish LAEs from lower-$z$ [OII] emitting galaxies. Despite a spectral resolving power, R $\sim800$, that cannot resolve the [OII] doublet, we demonstrate the ability to distinguish LAEs from foreground galaxies with 98.1% accuracy. We estimate a contamination rate of Ly$\alpha$ by [OII] of 1.2% and a Ly$\alpha$ recovery rate of 99.1% using the default ELiXer configuration. These rates meet the HETDEX science requirements.
Peer Review Status:Awaiting Review