UV/Optical/NIR spectroscopy

There are several large spectroscopic programs in COSMOS. The contact for the compilation of all available spectroscopic redshifts is Mara Salvato - mara [at] mpe.mpg.de

VIMOS Ultra Deep Survey (VUDS)

vuds spectra

VUDS (PI: O LeFevre) is a deep spectroscopic survey targeting 10,000 galaxies in the redshift range 2<z<6. Galaxies are selected on the basis of their photo-z and observed for up to 14h over 3650Å<λ<9350Å at a spectral resolution R=230 with the VIMOS multi-slit spectrograph on the ESO-VLT.

In COSMOS, VUDS covers 0.5 deg², where 3789 new redshifts have been obtained (median redshift z=3.2, highest reliable redshift z=6.1, see Le Fèvre et al. (2015) for more details). The data from the first data release (DR1) are public and can be obtained at http://cesam.lam.fr/vuds/DR1/. COSMOS team members are encouraged to contact VUDS members for joint analysis in synergy with other datasets.

For more information on DR1 see Tasca et al (2016). VUDS also has it's own Facebook page (https://www.facebook.com/vuds.survey/), Twitter account (@VUDS_Survey) and blog post on the CANDELS blog (http://candels-collaboration.blogspot.hr/)

The image shows 3Gyr of evolution at one glance: stacked display of 4000 VUDS spectra between redshift 2 and ~6 (left-hand axis), covering between ~10 and 13 billion years back into the history of the Universe (right-hand axis). Prominent absorption and emission lines like Hydrogen Lyman-Alpha can be traced, as well as rarer lines such as CIII.

Contact: Olivier LeFevre - olivier.lefevre [at] lam.fr ; Lidia Tasca - lidia.tasca [at] lam.fr


zCOSMOS Shallow: (PI: S. Lilly) Spent 270h on the VLT with VIMOS targeting 25,000 objects brighter than F814W<22.5 over the full 2 square degrees of COSMOS. The spectra cover 5000-8500Å with the R~500 MR-Red grating. For more information, see the release page at ESO. A comprehensive description of this data can be downloaded here.

zCOSMOS Deep: (PI: S. Lilly) Spent 270h on VLT with VIMOS targeting ~12,500 star forming galaxies color selected to lie at 1.4. The spectra cover 3600-6800Å.

Contact: Simon Lilly - simon.lilly [at] phys.ethz.ch ; Andreas Faisst - afaisst [at] caltech.edu


G10 is a re-analysis of the zCOSMOS-bright archival data by the Galaxy and Mass Assembly (GAMA) team containing 16.6k VIMOS redshifts. The catalogue contains the best publicly available redshifts for all sources in the Capak et al (2007) catalogue using zCOSMOS-bright, PRIMUS and the Ilbert et al photometeric redshifts. See Davies et al (2015) for further details. 

Contact: Luke Davies - luke.j.davies [at] uwa.edu.au


With the zC-SINF project a set of 30 star-forming galaxies at z~2 have been observed with the SINFONI integral field spectrograph at the VLT. The targets have been extracted from the zCOSMOS database for having a secure redshift, ensuring that the Halpha line is free from OH contamination and atmospheric absorptions, and a suitably bright star nearby for adaptive optics observations. The results are Halpha maps of individual galaxies with 1-2 kpc resolution, allowing to explore the dynamical status of the galaxy, map the surface density of star formation rate and explore non-gravitational gas motions such as galactic outflows.

Contact: Alvio Renzini - alvio.renzini [at] oapd.inaf.it ; Marcella Carollo - marcella.carollo [at] phys.ethz.ch


FMOS Low-resolution survey: (PIs: D. Sanders, J. Silverman, Y. Taniguchi, E. Treister) Uses the Fibre-fed Multi-Object Spectrograph (FMOS) on Subaru to conduct near-infrared spectroscopy (0.9-1.8 microns) primarily targeting AGN and IR-selected galaxies over the full COSMOS field. Redshifts and line fluxes are available for ~1000 galaxies. The survey paper is in preparation (Kartaltepe et al. 2015, in prep).

Contact: Jeyhan Kartaltepe - jeyhan [at] noao.edu

FMOS High-resolution survey: (PIs: D. Sanders and J. Silverman) Near-infrared spectroscopy in H- and J-band. Survey began in 2013 and is ongoing. This survey primarily targets star forming galaxies at z~1.5 (including BzK and IR-selected galaxies over the full COSMOS field. The survey paper has been submitted (Silverman et al. 2015). Contact Jeyhan Kartaltepe & John Silverman.

Contact: Jeyhan Kartaltepe - jeyhan [at] noao.edu and John Silverman - john.silverman [at] ipmu.jp


(PI: J. Kartaltepe 14 nights overall)

​Contact: Jeyhan Kartaltepe - jeyhan [at] noao.edu



(PI: Jehan Kartheltepe, Peter Capak, Mara Salvato, Günther Hasinger and Nick Scoville)

We have observed 82 DEIMOS masks in the COSMOS field over the time period 2007-2015. We have taken more than 7300 spectra, resulting in 4427 high-quality spectroscopic redshifts and 1472 intermediate quality redshifts.

The following plot shows a compilation of redshifts versus i magnitude. Filled symbols are high-quality, open symbols intermediate-quality and dots unidentified sources. Blue are from the Capak et al., red from the Hasinger et al sample. (Click to enlarge) All redshifts are entered in the Salvato et al. spectral catalogue compilation.

The 10k DEIMOS spectroscopy catalog (including spectra) is public and can be downloaded from IRSA.
The data-release paper (Hasinger et al. 2018) can be downloaded here.

For some spectral measurements at high redshifts (Ly-alpha) we refer to Mallery et al. (2012).

Contact: G. Hasinger - hasinger [at] ifa.hawaii.edu




Magellan: (PIs: C. Impey (Az), P. McCarthy (Carnegie), M. Elvis (CfA) and J. Huchra (CfA)) Targeted X-ray, optical, and IRAC selected AGN in cosmos with the IMACS spectrograph on Magellan over the full 2 square degree area.