The Local Volume Mapper 2 (LVM2) program will extend the capabilities of LVM in SDSS-V (Drory et al. 2024, Kollmeier et al. 2025) to the Northern Hemisphere, to conduct an unprecedented new IFU survey of the Local Group. It will also push the limits of the existing Southern LVM instrument to do the deepest optical spectroscopic characterization ever of selected regions of the Milky Way ISM. The ongoing SDSS-V LVM program demonstrated the power of high spatial resolution ultra-wide-field IFU spectroscopy, by producing the first optical IFU data set of the entire southern Milky Way plane and the Magellanic Clouds, covering ~4000 square degrees of sky.
The LVM2-South survey will dramatically expand the sources in which critical “extremely-faint emission line science” can be carried out, and will produce the first comprehensive spectral characterization of low surface brightness emission in our Galaxy. The LVM2-North survey (also known as the Local Group Explorer) will create IFU maps of M31, M33 and a sample of dwarf galaxies within 5 Mpc, providing a view into stellar feedback physics, linking stars and gas, as well as stellar populations and star formation histories across a wide range of physical conditions and local environments. LVM2 will link the galactic and extragalactic regimes, exploring star forming regions over a range of scales and environments unattainable before now. LVM2 is being conducted with 2 primary subsurveys:
LVM2 North Survey/Local Group Explorer (LGE):
In LVM2 North, we will mount a new wide-field (2×2 arcmin) IFU on a 2.5-m class telescope in the Northern hemisphere, feeding a twin cluster of LVM spectrographs, and use it to map M31 and M33, matching the coverage of the HST-PHAT+PHAST and PHATTER surveys. This enables a spaxel size of 2.5 arcsec and spatial resolutions of <0.1 pc within our Galaxy, ~10 pc (within the local group) and up to ~50pc (for more distant galaxies). We will also map a sample of 57 local dwarf galaxies at <5 Mpc distance. Following a strategy well-proven in the ongoing SDSS-V LVM survey of the LMC/SMC.
LVM2 South Survey/The Interstellar Explorer (ISE) Survey:
In LVM2 South, deeper observations with the LVM-I at LCO in selected areas, together with an expansion of the spatial coverage, will enable the exploration of previously unstudied regions of the Milky Way, mapping low–surface-brightness Galactic structures, particularly toward the Galactic center. The increased depth will enable the detection of extremely faint emission lines from HII regions, planetary nebulae, and supernova remnants, providing key diagnostics of ionized gas. In particular, measurements of extremely faint heavy-element recombination lines will allow robust, largely temperature-independent determinations of chemical abundances.
Contact information
For more information on the Local Volume Mapper 2, contact the AS5/LMV-2 Program Heads: Niv Drory (University of Texas at Austin/McDonald Observatory) and Guillermo Blanc (Carnegie Observatories/Las Campanas Observatory)
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