LVMI

Local Volume Mapper Instrument (LVM-I)

LVM-I is a new facility for SDSS-V, with an instrument that is specifically tailored to meet the Local Volume Mapper survey requirements. The LVM-I team is responsible for producing a new building, four telescopes, an integral field unit, fiber bundle, and three spectrographs. In its final configuration, LVM-I will operate autonomously to execute an integral-field survey of the interstellar medium in the Milky Way and Magellanic Clouds. The four 16-cm telescopes are custom-designed and built for the LVM-I project. One telescope performs science observations, while the other three are devoted to real-time calibration observations of the sky and standard stars. The fiber bundle carries fibers from the telescopes to the spectrographs via a “Sorting Hat” that distributes the fibers. The LVM-I will be commissioned at Las Campanas Observatory, and we plan to expand LVM-I into the Northern Hemisphere with a second-generation facility.

A rendering of the LVM-I enclosure superimposed on “robot ridge” at Las Campanas Observatory. Credit: Guillermo Blanc, LCO.

Our highest level goal is to produce an integral-field survey that covers 48 deg2/month. Each spaxel subtends <1 parsec at 3 kpc distance (~36” diameter spaxels). The spectra cover a broad range of wavelengths (360 nm — 980 nm) at a spectral resolution of 4,000 at H⍺ (able to measure velocities of ~10 km/s). For typical exposures, H⍺ radiances of about 10-17 erg/s/cm2/arcsec2 will be robustly detected on its ~1,800 spaxels. LVM’s coverage of ~2800 deg2 in the Milky Way and 100 deg2 in the Magellanic Clouds will be 3-4 orders of magnitude larger than any existing IFU dataset.

The LVM-I roll on/off enclosure solid model. The four telescopes are fed by siderostats (middle) while a fiber bundle pipes the light from the telescopes into the three spectrographs (double-walled enclosure to the right of the telescopes). Credit: Tom Herbst, MPIA
A solid model of the LVM-I telescope-to-spectrograph fiber run. Fibers from the four telescopes are distributed and fed into three spectrographs through the “Sorting Hat”. Credit: Tobias Feger, AAO.

The LVM-I team includes the following key personnel:

  • Team Lead: Nick Konidaris (Carnegie)
  • Project Manager: Cynthia Froning (UT)
  • Lead Engineer: Tony Hebert (Carnegie)
  • Telescopes: Tom Herbst (MPIA), Peter Bizenberger (MPIA), Alica Lanz (Carnegie)
  • Enclosures: Guillermo Blanc (Carnegie)
  • Fibers: Scott Case (AAO), Tobias Feger (AAO), Ross Zhelm (AAO)
  • Spectrographs: Pavan Bilgi (Carnegie)
  • Software: Soojong Pak (KHU)