51 research outputs found
The Keck Cosmic Web Imager
We are designing the Keck Cosmic Web Imager (KCWI) as a new facility instrument for the Keck II telescope at the W. M. Keck Observatory (WMKO). KCWI is based on the Cosmic Web Imager (CWI), an instrument that has recently had first light at the Hale Telescope. KCWI is a wide-field integral-field spectrograph (IFS) optimized for precision sky limited spectroscopy of low surface brightness phenomena. KCWI will feature high throughput, and flexibility in field of view (FOV), spatial sampling, bandpass, and spectral resolution. KCWI will provide full wavelength coverage (0.35 to 1.05 μm) using optimized blue and red channels. KCWI will provide a unique and complementary capability at WMKO (optical band integral field spectroscopy) that is directly connected to one of the Observatory's strategic goals (faint object, high precision spectroscopy), at a modest cost and on a competitive time scale, made possible by its simple concept and the prior demonstration of CWI
StoRIR: Stochastic Room Impulse Response Generation for Audio Data Augmentation
In this paper we introduce StoRIR - a stochastic room impulse response
generation method dedicated to audio data augmentation in machine learning
applications. This technique, in contrary to geometrical methods like
image-source or ray tracing, does not require prior definition of room
geometry, absorption coefficients or microphone and source placement and is
dependent solely on the acoustic parameters of the room. The method is
intuitive, easy to implement and allows to generate RIRs of very complicated
enclosures. We show that StoRIR, when used for audio data augmentation in a
speech enhancement task, allows deep learning models to achieve better results
on a wide range of metrics than when using the conventional image-source
method, effectively improving many of them by more than 5 %. We publish a
Python implementation of StoRIR onlineComment: Accepted for INTERSPEECH 202
The FLASHES Survey I: Integral Field Spectroscopy of the CGM around 48 QSOs
We present the pilot study component of the Fluorescent Lyman-Alpha
Structures in High-z Environments (FLASHES) Survey; the largest integral-field
spectroscopy survey to date of the circumgalactic medium at . We
observed 48 quasar fields between 2015 and 2018 with the Palomar Cosmic Web
Imager (Matuszewski et al. 2010). Extended HI Lyman- emission
is discovered around 42/48 of the observed quasars, ranging in projected,
flux-weighted radius from 21-71 proper kiloparsecs (pkpc), with 26 nebulae
exceeding in effective diameter. The circularly averaged
surface brightness radial profile peaks at a maximum of
( adjusted for
cosmological dimming) and luminosities range from
to
. The emission appears to have a highly
eccentric morphology and a maximum covering factor of ( for giant
nebulae). On average, the nebular spectra are red-shifted with respect to both
the systemic redshift and Ly peak of the quasar spectrum. The
integrated spectra of the nebulae mostly have single or double-peaked line
shapes with global dispersions ranging from to
, though the individual (Gaussian) components of lines
with complex shapes mostly appear to have dispersions
, and the flux-weighted velocity centroids of the lines
vary by thousands of with respect to the systemic QSO
redshifts. Finally, the root-mean-square velocities of the nebulae are found to
be consistent with gravitational motions expected in dark matter halos of mass
. We compare these results to existing
surveys at both higher and lower redshift
FIREBALL: Detector, data acquisition and reduction
The Faint Intergalactic Redshifted Emission Balloon (FIREBALL) had its first scientific flight in June 2009. The instrument combines microchannel plate detector technology with fiber-fed integral field spectroscopy on an unstable stratospheric balloon gondola platform. This unique combination poses a series of calibration and data reduction challenges that must be addressed and resolved to allow for accurate data analysis. We discuss our approach and some of the methods we are employing to accomplish this task
FIREBALL: Instrument pointing and aspect reconstruction
The Faint Intergalactic Redshifted Emission Balloon (FIREBALL) had its first scientific flight in June 2009. The instrument is a 1 meter class balloon-borne telescope equipped with a vacuum-ultraviolet integral field spectrograph intended to detect emission from the inter-galactic medium at redshifts 0.3 < z < 1.0. The scientific goals and the challenging environment place strict constraints on the pointing and tracking systems of the gondola. In this manuscript we briefly review our pointing requirements, discuss the methods and solutions used to meet those requirements, and present the aspect reconstruction results from the first successful scientific flight
The Cosmic Web Imager: An integral field spectrograph for the Hale Telescope at Palomar Observatory: Instrument design and first results
We describe the Cosmic Web Imager (CWI), a UV-VIS integral field spectrograph designed for the Hale 200" telescope at the Palomar Observatory. CWI has been built specifically for the observation of diffuse radiation. The instrument field of view is 60" x 40" with spectral resolving power of R ~5000 and seeing limited spatial resolution. It utilizes volume phase holographic gratings and is intended to cover the spectral range 3800Å to 9500Å with an instantaneous bandwidth of ~450Å. CWI saw first light in July 2009, and conducted its first successful scientific observations in May 2010
- …