Institute of Astronomy

Data Products

Data Releases

LVL Portal at the NASA/IPAC Infrared Science Archive: Cumulative dataset from all deliveries.
LVL Portal at the Spitzer Science Center: Instructions for accessing data from individual data releases.

Data Product Description

The LVL sample contains 258 galaxies, which have been mapped with both IRAC (4 bands) and MIPS (3 bands). In addition, ancillary data products consisting of images in the narrow-band Hα line emission and broad-band R (from the ground) and the UV continuum (2 bands from GALEX) are also available for most of the sample, and has been delivered as part of the LVL project. A fraction of galaxies in LVL sample were observed by previous Spitzer programs and are already available in the Spitzer Archive (57 for MIPS and 78 for IRAC ); the archival images have been re-processed by our team to provide a common product together with the rest of the LVL sample. Of the galaxies with Spitzer images, 33 are from the SINGS project.

We have delivered data for 256 of the galaxies in the LVL sample. The two remaining galaxies, the Magellanic Clouds (SMC and LMC), have been observed and delivered as part of other Spitzer Legacy Programs,SAGE (P.I.:Meixner) and SAGE-SMC (P.I.:Gordon). The final list of data products is as follows:

  • IRAC mosaics of 256 galaxies;
  • MIPS mosaics of 256 galaxies;
  • Optical images in Hα and R for 170 galaxies. For the majority of the remaining galaxies, Hα images are available to the community through NED.
  • GALEX FUV (1529 A) and NUV (2312 A) images of 251 galaxies. The remaining galaxies are unobservable by GALEX due to the bright object limit constraints of the UV detectors.

LVL data products include:

1. IRAC : four astrometrically aligned images (one image per band) for each galaxy, as a single extension FITS file, calibrated in Myr/sr, and with standard WCS information.

2. MIPS : three astrometrically aligned images, one for each MIPS channel, per galaxy, with pixels size of 1.5, 4.5, and 9.0 arcsec (24, 70, and 160 μm, respectively), calibrated in MJy/sr and with constant background level removed. FITS files will have the same characteristics as the IRAC data products.

Ancillary Data

1. Optical data: Optical imaging data in a standard R broad-band filter and in narrow-band filters at the wavelength of the Hα+[NII] emission, plus continuum-substracted Hα+[NII] images have been made publically available. The optical images are stored in single-extension FITS files, and are flux and astrometrically calibrated (with standard WCS headers). The Hα images are be continuum-subtracted. The data have been obtained by Kennicutt et al. 2008.

2. GALEX UV images: GALEX ultraviolet imaging for the LVL galaxies have been obtained through the 11 Mpc Hα UV Galaxy Survey (11HUGS) Cycle 1 (P.I.: R. C. Kennicutt) and Cycle 4 (P.I.: J. C. Lee) programs; a Cycle 3 ACS Nearby Galaxies Treasury Survey follow-up program (P.I.: E. Skillman); the GALEX team's Nearby Galaxaies Survey (NGS), Medium-deep Imaging Survey (MIS), and all-sky Imaging Survey (AIS); and individual GI programs with data available through the GALEX archive.The combined programs provide UV data for 251 of the 258 galaxies in the LVL sample. The remaining 7 galaxies cannot be observed due to bright-object avoidance constraints. The ensemble dataset is described in detail in Lee et al. 2011.

For each galaxy, 4 intensity images, two for each GALEX band (one image per band containing the full GALEX field-of-view, 1.2 degrees, and the other cropped to a radius of 4 times D_25), have been delivered, with 5 arcsec resolution. GALEX pipeline processed images are also available at the Multimission Archive at Space Telescope.

3. High level products of the HST optical images obtained as part of the ACS Nearby Galaxy Survey Treasury (ANGST) are available from here and from the ANGST MAST site.

Last updated 2011 February.

Page last updated: 11 March 2011 at 22:41