WEAVE-LOFAR

 
 

I am the science team leader of the WEAVE-LOFAR survey, which will be the primary source of spectroscopic information for the LOFAR Surveys Key Science Project.


Starting in 2018, we will use the new WHT Enhanced Area Velocity Explorer (WEAVE) multi-object spectrograph on the William Herschel Telescope to obtain optical (370-970 nm) spectra of hundreds of thousands of radio sources. These radio sources will be selected from the LOFAR telescope Surveys Key Science Project (Röttgering et al. 2011) which are being observed at low radio frequencies (120-150 MHz). Like the LOFAR Surveys KSP, WEAVE-LOFAR will have adopt a “wedding cake” strategy to efficiently populate the redshift-luminosity plane, with three tiers:


  1. the WIDE, covering around 10k deg2 to S150 MHz > 10 mJy in the galactic halo;

  2. the MID, surveying 650 deg2 to S150 MHz > 1 mJy, located primarily in the HETDEX northern field (1200+55) and the HATLAS NGP (1300+29);

  3. the DEEP, covering a few 10s of deg2 in the best areas of multi-wavelength coverage in the northern sky, including the Lockman Hole (1050+57), ELAIS-N1 (1610+54), Boötes (1430+34) and NEP (1800+66) fields.


Because the unique WEAVE-LOFAR sample is defined at low radio frequencies (which selects sources based on their activity), WEAVE-LOFAR will be very efficient, and observations will target areas of the sky with the best multi-wavelength data of every scale to ensure that the scientific return is maximised.


In this way, WEAVE-LOFAR will enable us to study both rare high-value objects, as well as the fainter and more numerous sources which dominate the cosmic star formation & accretion histories, with large statistical significance and therefore unprecedented rigour. WEAVE-LOFAR will also perform resolved spectroscopy of large numbers of sources using the WEAVE mIFU and LIFU modes, enabling detailed studies of individual systems, which can then be understood within the context provided by the tiered multi-object survey. The WEAVE-LOFAR science case is very broad (as you’d expect for a survey that will produce more than a million spectra), but includes the following themes:


  1. cosmic star formation history;

  2. the history of accretion and AGN driven feedback;

  3. probing the epoch of re-ionization;

  4. cosmology;

  5. cluster halos & relics;

  6. radio galaxies, Lyman alpha haloes and proto-cluster environments.


WEAVE-LOFAR will make a range of exquisite measurements, ranging from determining the nature of the faint radio source population, clarifying the relationship between star formation and accretion over the majority of cosmic history, finding z > 6 radio galaxies to study the timescale of the re-ionization process, searching for evidence of stellar and AGN feedback, to deriving a complete census of AGN in the Universe.


Some more details of the WEAVE-LOFAR survey are in Smith (2015), and Smith et al. (2016) but it will be described in detail in Smith et al (in prep).


WEAVE will hit the sky in early 2018; watch this space!


Last update: 25/04/2016

The first WEAVE LOFAR Science Team meeting was held in Oxford on March 16-17 2016, details of the meeting are at this link!

New webpage: from now on, the most up-to-date WEAVE-LOFAR webpage can be found at: www.ing.iac.es/weave/weavelofar/