Date: 16th & 17th November 2022
Location: Room V020 @ Enterprise Hub, University of Hertfordshire, UK
Hosted by: The Centre for Astrophysics Research (CAR)

The workshop will also be held fully online via zoom (see the workshop emails for the links).

The workshop will include:
(a) presentations on the latest L-Galaxies code developments and results from various groups
(b) discussions about future plans for the model and possible collaborations
(c) a "coding session" to get new users up-and-running with the latest public version of the code, L-Galaxies 2020

If you are interested in attending, either in-person or virtually, please contact the main organiser (Rob Yates) at:
r.yates3 -at- herts.ac.uk

The final workshop schedule can be found here: Workshop schedule

On the first day, we will meet at the workshop venue itself: Room V020 (ground floor) of the Enterprise Hub at 08:45.

We have endeavoured to provide enough time for talks, discussion, and coding assistance for new users, while also trying to arrange the schedule to best fit virtual attendees joining from other time zones.

Talks will be 20 mins + 5 mins for questions. Please send a pdf copy of your talk slides one day in advance to r.yates3 -at- herts.ac.uk
The "Main Developer Discussion" session on Day 2 is reserved for L-Galaxies main developers only.

The University of Hertfordshire is situated between the towns of Hatfield and St Albans.
It is divided into two main campuses, the College Lane campus and the De Havilland campus. The Enterprise Hub (where the workshop will be held) is on the De Havilland campus.

Information on how to reach the De Havilland campus is provided here: Getting here
A campus map (showing the Enterprise Hub, bus stops, and parking) is here: Campus map
We have also provided additional travel and accommodation info below.

Unfortunately, public transport in the UK isn't the cheapest, so be prepared to pay a little more than expected!
As of 9th November, there don't appear to be any train or bus strikes planned for the dates of the workshop. The workshop LOC will keep a close eye on any further developements, and will keep you informed.

Arriving by plane
The closest airport to the university is London Luton [LTN]. Trains from the airport to St Albans [SAC] take around 10 mins, see here: Trains from Luton airport
Once at St Albans station, the regional UNO (601 and 602) buses will take you to "UH de Havilland Campus, Hatfield Business Park". Alternatively, the Arriva (301 and 302) buses will take you to the other nearby bus stop, "Hatfield The Comet Hotel". The bus journey normally takes ~20 mins. Some other buses may also link St Albans to the De Havilland campus. See here: Bus timetables
Taxis are also available to book from St Albans station, e.g. AAA Taxis (+44 1707 888777).

There is also a regular National Express bus between Stansted airport and Hatfield (close to the De Havilland campus), which takes ~1hr 10mins and costs ~£7. If you're arriving at other airports (e.g. Gatwick or Heathrow), a train journey into London is usually necessary, before taking the London Kings Cross train north to the university, as detailed below.

Arriving by train
Hatfield [HAT] and St Albans [SAC] stations are served by regular trains from London Kings Cross [KGX]. The train journey normally takes 20-25 mins. Tickets can be purchased from e.g. National Rail or Trainline

Once at Hatfield or St Albans station, the regional UNO (601 and 602) buses will take you to "UH de Havilland Campus, Hatfield Business Park". Alternatively, the Arriva (301 and 302) buses will take you to the other nearby bus stop, "Hatfield The Comet Hotel". The bus journey normally takes ~10 mins from Hatfield station, and ~20 mins from St Albans station. Some other buses also link Hatfield/St Albans to the De Havilland campus. See here: UNOBus timetables, Intalink timetables
Taxis are also available to book from both Hatfield or St Albans station, e.g. AAA Taxis (+44 1707 888777).

Arriving by car
The university is situated just off the A1(M) (junction 3).
Parking on campus is managed by the Hozah online payment system. Visitors can park in car park ML2.
Alternatively, there is a "free" park-and-ride in operation (a ticket for the 10-min shuttle bus costs £1).
For more information (including a map of the car park locations), see here: Parking on campus

• The Comet Hotel, situated next to the De Havilland campus, is a 5 min walk from the workshop venue.
• Mercure Hatfield Oak, situated next to the College Lane campus, is a 30 min walk from the workshop venue. A free shuttle bus between the two campuses is also available. See here: Shuttle bus
• Travel Lodge Hatfield Central, situated in Hatfield, is a 10 min walk from the workshop venue.
• Travel Lodge St Albans City, situated in St Albans, is a 45 min bus ride (UNO bus 601 or 602) from the workshop venue.
• Premier Inn St Albans City Centre, situated in St Albans, is a 45 min bus ride (UNO bus 601 or 602) from the workshop venue.

Discounted rates may be available at the Comet Hotel and Mercure Hatfield Oak, as visitors to the University. Quote the promotional code "HERTS" when making your booking to check this.

The workshop dinner will be held at The Crown pub in St Albans at 18:45 on Wednesday 16th November (see the menu here).

The best way to get there from the workshop venue is probably one of the following:

• The Arriva 302 bus, departing Hatfield The Comet Hotel at 18:13 and arriving at Granville Road at 18:30.
• The UNO 602 bus, departing UH De Havilland campus (Stop Q) at 18:27 and arriving at Granville Road at 18:43.

The last 602 bus back to the De Havilland campus leaves St Albans around 22:00. After that, a taxi/Uber will likely be necessary to get back to Hatfield.
Unfortunately, Uni Hertfordshire is unable to cover the cost of the workshop dinner.

Instructions on how to download, install, compile, and run L-Galaxies 2020 and its associated files on different operating systems are here:
On Linux

On Mac OS

On Windows

Note that the minimum storage requirment to run the test version of L-Galaxies 2020 presented at the workshop is ~3.5 GB (including the output file generated). For more information on L-Galaxies storage requirements, see below.

Storage requirements
For a basic L-Galaxies 2020 installation, (a) code files, (b) some dark matter merger-tree files (i.e. "treefiles"), and (c) some spectrophotometric tables are needed. In most cases, only a handful of treefiles are required to return a representative sub-volume containing a realistic range of galaxies (i.e. to roughly reproduce the observed stellar mass function at z=0). The total storage space requirements for these basic files are:

When run on Millennium-I:
Minimum: ~2.5 GB (to run on treefile 5)
Typical: ~9.2 GB (to run on treefiles 0-9)
Maximum: ~402.2 GB (to run on the full Millennium-I, 512 treefiles)

When run on Millennium-II:
Minimum: ~2.0 GB (to run on a single treefile - WARNING: not a representative sub-volume)
Typical: ~6.3 GB (to run on treefiles 40-79)
Maximum: ~186.7 GB (to run on the full Millennium-II, 512 treefiles)

Note that the above estimates do not include the space required to store newly-generated output files. The sizes of these can vary greatly, depending on the number of treefiles used, whether "snapshot" or "galaxytree" mode is chosen, and (in the snapshot mode case) which redshift is outputted. A rough guide to the typical size of each output file for the L-Galaxies 2020 "Default Model" is provided here (for a full set out output files from the whole simulation, multiply by 512):

Outputs when run on Millennium-I:
Snapshot mode: ~50 MB - 1.5 GB each
Galaxytree mode: ~10-25 GB each

Outputs when run on Millennium-II:
Snapshot mode: ~25-350 MB each (excluding treefile 0)
Galaxytree mode: ~10-25 GB each