Ionized gas is a key component for understanding star formation within galaxies. As part of SIGNALS, a survey that focuses on the emission regions of about 40 nearby star-forming galaxies, NGC 925 was observed with SITELLE, an imaging Fourier transform spectrometer for the optical spectrum built in Qu´ebec City (U. Laval and ABB) and installed at the Canada-France-Hawaii Telescope. This work mainly focuses on HII regions; establishing the physical characteristics of these regions will yield reliable insight regarding the influence of local environments on star formation and the different star-forming mechanisms at play. At a distance of 9.2 Mpc, NGC 925 is a fine candidate in SIGNALS framework, due to SITELLE’s high spatial resolution of 0.32”/pixel and large field of view of 11’x11’, HII regions are differentiated from one another over the whole galaxy. Using Hα to locate emission regions, we compute BPT diagrams for these regions using the emission line ratios [OIII]/Hβ and [NII]/Hα. A catalog of HII regions is compiled from these diagrams. The preliminary results presented in this work (i.e., a young bar, an asymmetric distribution of HII regions and recent star formation) suggest that NGC 925 may be the result of an interaction with another member of NGC 1023 group. Simulations of galaxy interactions and multiwavelength observations will be acquired to confirm this hypothesis.
In the Roman era, wide-field, deep, visible-to-near infrared images will revolutionize our understanding of galaxy evolution (e.g. environments, morphologies, masses, colors). The legacy value of Roman images and low-resolution spectra (with Roman’s prism and grism) will be greatly enhanced by massively multiplexed ground-based observations in the near – future and simultaneously allow us to leverage an impressive bounty of archived spectra from Maunakea facilities. We plan to enhance ground-based NIR spectra of astrophysically interesting objects with ground-sky spectra, atmospheric data, HST spectra and images, and machine learning techniques proven to predict galaxy spectra from images.
The SITELLE Imaging Fourier Transform Spectrometer was successfully commissioned at the Canada France Hawaii Telescope starting in July 2015. Here we discuss the commissioning process, the outcome of the early tests on-sky as well as the ensuing work to optimize the modulation efficiency at large optical path difference and the image quality of the instrument.
We present new data obtained with SpIOMM, the imaging Fourier transform spectrometer attached to the 1.6-m
telescope of the Observatoire du Mont-Megantic in Québec. Recent technical and data reduction improvements have
significantly increased SpIOMM's capabilities to observe fainter objects or weaker nebular lines, as well as continuum
sources and absorption lines, and to increase its modulation efficiency in the near ultraviolet. To illustrate these
improvements, we present data on the supernova remnant Cas A, planetary nebulae M27 and M97, the Wolf-Rayet ring
nebula M1-67, spiral galaxies M63 and NGC 3344, as well as the interacting pair of galaxies Arp 84.
We describe the concept of a new instrument for the Canada-France-Hawaii telescope (CFHT), SITELLE (Spectromètre
Imageur à Transformée de Fourier pour l'Etude en Long et en Large de raies d'Emission), as well as a science case and
a technical study of its preliminary design. SITELLE will be an imaging Fourier transform spectrometer capable of
obtaining the visible (350 nm - 950 nm) spectrum of every source of light in a field of view of 15 arcminutes, with 100%
spatial coverage and a spectral resolution ranging from R = 1 (deep panchromatic image) to R = 104 (for gas dynamics).
SITELLE will cover a field of view 100 to 1000 times larger than traditional integral field spectrographs, such as
GMOS-IFU on Gemini or the future MUSE on the VLT. It is a legacy from BEAR, the first imaging FTS installed on
the CFHT and the direct successor of SpIOMM, a similar instrument attached to the 1.6-m telescope of the Observatoire
du Mont-Mégantic in Québec. SITELLE will be used to study the structure and kinematics of HII regions and ejecta
around evolved stars in the Milky Way, emission-line stars in clusters, abundances in nearby gas-rich galaxies, and the
star formation rate in distant galaxies.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.