• A source located at the edge of the central 3x3 spaxel box.
• Un-chopped spectroscopy.

There are two excellent starting points for learning how to use PACS spectroscopy data. We recommend strongly that you start by reading the Quick Start Guide to Spectroscopy (also known as the PACS Data Reduction Launchpad: Spectroscopy), which summarises the PACS spectroscopy observing modes, data products, calibration uncertainties and science-readiness of the different PACS spectroscopy products.

There is also a Herschel Science Centre short videotutorial called Starting with PACS Spectroscopy, which will walk you through the basics of PACS Spectroscopy. You can find the short videotutorial here:

https://www.youtube.com/watch?v=rcY487Z9Kyg

This short videotutorial will explain the three basic observing modes for PACS spectroscopy and their uses, how to determine from the Herschel Science Archive (HSA), or from the FITs header in which observing mode an observation was made, detailing the main keywords that users should be familiar with. For each product, you will find out which data products you need and what products are available at different levels for the different observing modes. You will learn what the PACS cubes are and their contents for different modes, PACS data tables and so-called slices for each mode, which are the different presentations of the cubes and tables. You will learn what a PACS spectroscopy observation looks like in the HSA and what post-processing (if any) is required for sources of different sizes. Finally, you will see which Highly Processed Data Products (Expert Reduced Data Products) have been prepared by the experts at the Herschel Science Centre for particularly difficult cases.

If your observation is a spectral map, the products are 3-D spectral cubes and not 1-D spectra. This makes saving data more difficult, as no tools were implemented in HIPE to save a 3-D structure as a text file.

So, unlike for single point spectra, you cannot you cannot use the "Save to text file" option on a spectral cube. So, first you must extract a 1-D spectrum from a pre-selected cube pixel (aka spaxel).

The Herschel Science Centre has created a short videotutorial that explains how to do this. You can find it on the Herschel Academy YouTube channel at:

Saving a 3-D SPIRE FTS spectral cube as a 1D spectrum

• Search by target name.
• Search by coordinates (in a radius around a particular position).
• Search by catalogue (for example, in the Herschel PACS, or Herschel SPIRE Point Source Catalogues, or for data published as a Highly Processed Data Product, or... etc.)
• Search for unpublished observations.

Name searches in the HSA only work by cross-referencing with either the SIMBAD database of (mainly) stellar objects or the NED database of extragalactic objects that both, logically, exclude Solar System Objects. These must be identified using their NAIF ID, selecting the “NAIF ID” tab, as there is no name-searcher available to the HSA for Solar System Objects.

For comets and asteroids, the NAIF ID is a unique, 7-digit identifier. The NAIF ID for comets has the format 100****, while for numbered asteroids, it is 2******, with the digits following the leading “2” being the asteroid number. A few objects observed by Herschel were un-numbered asteroids with lower-quality orbits, which have the format 3******. You may also input a text file with a list of NAIF IDs to check.

The HSA uses wild-cards automatically. If you enter 100 and press Search, you will obtain a listing of all comet observations.

For planets and their satellites, the NAIF ID is 3-digits starting with the planet number in order of distance from the Sun (Mars = 4, Jupiter = 5, etc). The planet itself is 499, 599, 699, … while the satellites are the planet number followed by the satellite number so, Titan, or Saturn VI, is 606, while Callisto, Jupiter IV, is 504.

To return the NAIF ID for any named Solar System Object, enter the following line in a browser:

https://ssd.jpl.nasa.gov/x/smb_spk.cgi?OPTION=Look+up&OBJECT=ceres

Just replace the name "ceres" with the solar system object that you wish to identify (name - if named [e.g. Haumea], number [e.g. 2000], or provisional designation [e.g. 1950 DA]).

The Herschel Science Centre has produced a useful short videotutorial, How to use the Herschel Science Archive User Interface, to show new users how to access and use the Herschel Science Archive and about the data products that are available within it. You can find this short videotutorial here:

http://youtu.be/IgGNpUgubkw

Answer supplied by Eva Verdugo:

The Herschel Science Archive includes in the “Basic Search” panel a field called "Access Status" that allows searching by "Public", or by "Restricted" observations. Some observations were taken in non-standard modes, or with special set-ups only used for calibration and engineering purposes and their access is therefore restricted by default to Herschel experts only. If for any reason you still think you need to gain access to any of these observations please raise a ticket at this HSC Helpdesk indicating the reason and we will assist you providing technical advice on the additional caveats you need to consider and the limitations affecting the observation for any potential use.

• How many observations there are in the HSA for this target, their status and quality.
• What publications have been produced from each observation.
• What User Provided Data Products are available for each observation.
• What Highly Processed Data Products are available for each observation and how these compare with the standard pipeline products.
• How to filter searches to obtain more, or less information.