.. _astroquery.ipac.irsa.irsa_dust: *********************************************************************** IRSA Dust Extinction Service Queries (`astroquery.ipac.irsa.irsa_dust`) *********************************************************************** Getting started =============== This module can be used to query the `IRSA Dust Extinction Service`_. Fetch images ------------ Retrieve the image cut-outs for the specified object name or coordinates. The images fetched in the FITS format and the result is returned as a list of `~astropy.io.fits.HDUList` objects. For all image queries, the radius may be optionally specified. If missing the radius defaults to 5 degrees. Note that radius may be specified in any appropriate unit, however it must fall in the range of 2 to 37.5 degrees. .. doctest-remote-data:: >>> from astroquery.ipac.irsa.irsa_dust import IrsaDust >>> image_list = IrsaDust.get_images("m81") # doctest: +IGNORE_OUTPUT Downloading http://irsa.ipac.caltech.edu//workspace/TMP_pdTImE_1525/DUST/m81.v0001/p414Dust.fits |===========================================| 331k/331k (100.00%) 15s Downloading http://irsa.ipac.caltech.edu//workspace/TMP_pdTImE_1525/DUST/m81.v0001/p414i100.fits |===========================================| 331k/331k (100.00%) 13s Downloading http://irsa.ipac.caltech.edu//workspace/TMP_pdTImE_1525/DUST/m81.v0001/p414temp.fits |===========================================| 331k/331k (100.00%) 05s >>> image_list # doctest: +IGNORE_OUTPUT [[], [], []] Image queries return cutouts for 3 images - E(B-V) reddening, 100 micron intensity, and dust temperature maps. If only the image of a particular type is required, then this may be specified by using the ``image_type`` keyword argument to the :meth:`~astroquery.ipac.irsa.irsa_dust.IrsaDustClass.get_images` method. It can take on one of the three values ``ebv``, ``100um`` and ``temperature``, corresponding to each of the 3 kinds of images: .. doctest-remote-data:: >>> from astroquery.ipac.irsa.irsa_dust import IrsaDust >>> import astropy.units as u >>> image = IrsaDust.get_images("m81", image_type="100um", radius=2*u.deg) # doctest: +IGNORE_OUTPUT Downloading http://irsa.ipac.caltech.edu//workspace/TMP_007Vob_24557/DUST/m81.v0001/p414i100.fits |===========================================| 149k/149k (100.00%) 02s >>> image # doctest: +IGNORE_OUTPUT [[]] The image types that are available can also be listed out any time: .. doctest-remote-data:: >>> from astroquery.ipac.irsa.irsa_dust import IrsaDust >>> IrsaDust.list_image_types() ['temperature', 'ebv', '100um'] The target may also be specified via coordinates passed as strings. Examples of acceptable coordinate strings can be found on this `IRSA DUST coordinates description page`_. .. doctest-remote-data:: >>> from astroquery.ipac.irsa.irsa_dust import IrsaDust >>> import astropy.coordinates as coord >>> import astropy.units as u >>> image_list = IrsaDust.get_images("17h44m34s -27d59m13s", radius=2.0 * u.deg) # doctest: +IGNORE_OUTPUT Downloading http://irsa.ipac.caltech.edu//workspace/TMP_46IWzq_9460/DUST/17h44m34s_-27d59m13s.v0001/p118Dust.fits |==============================| 57k/ 57k (100.00%) 00s Downloading http://irsa.ipac.caltech.edu//workspace/TMP_46IWzq_9460/DUST/17h44m34s_-27d59m13s.v0001/p118i100.fits |==============================| 57k/ 57k (100.00%) 00s Downloading http://irsa.ipac.caltech.edu//workspace/TMP_46IWzq_9460/DUST/17h44m34s_-27d59m13s.v0001/p118temp.fits |==============================| 57k/ 57k (100.00%) 00s A list having the download links for the FITS image may also be fetched, rather than the actual images, via the :meth:`~astroquery.ipac.irsa.irsa_dust.IrsaDustClass.get_image_list` method. This also supports the ``image_type`` argument, in the same way as described for :meth:`~astroquery.ipac.irsa.irsa_dust.IrsaDustClass.get_images`. .. doctest-remote-data:: >>> from astroquery.ipac.irsa.irsa_dust import IrsaDust >>> import astropy.coordinates as coord >>> import astropy.units as u >>> coo = coord.SkyCoord(34.5565*u.deg, 54.2321*u.deg, frame='galactic') >>> image_urls = IrsaDust.get_image_list(coo) >>> image_urls # doctest: +IGNORE_OUTPUT ['http://irsa.ipac.caltech.edu//workspace/TMP_gB3awn_6492/DUST/34.5565_54.2321_gal.v0001/p292Dust.fits', 'http://irsa.ipac.caltech.edu//workspace/TMP_gB3awn_6492/DUST/34.5565_54.2321_gal.v0001/p292i100.fits', 'http://irsa.ipac.caltech.edu//workspace/TMP_gB3awn_6492/DUST/34.5565_54.2321_gal.v0001/p292temp.fits'] Fetching the extinction table ----------------------------- This fetches the extinction table as a `~astropy.table.Table`. The input parameters are the same as in the queries discussed above, namely the target string and optionally a radius value: .. doctest-remote-data:: >>> from astroquery.ipac.irsa.irsa_dust import IrsaDust >>> import astropy.coordinates as coord >>> import astropy.units as u >>> # "22h57m57.5s +26d09m00.09s Equatorial B1950" >>> coo = coord.SkyCoord("22h57m57.5s +26d09m00.09s", frame='fk4') >>> table = IrsaDust.get_extinction_table(coo) # doctest: +IGNORE_OUTPUT Downloading http://irsa.ipac.caltech.edu//workspace/TMP_wuevFn_3781/DUST/345.094229457703_26.418650782801027.v0001/extinction.tbl |=======================================================================================| 4.4k/4.4k (100.00%) 0s >>> print(table) Filter_name LamEff A_over_E_B_V_SandF A_SandF A_over_E_B_V_SFD A_SFD micron mag mag ----------- ------ ------------------ ------- ---------------- ----- CTIO U 0.3734 4.107 0.174 4.968 0.21 CTIO B 0.4309 3.641 0.154 4.325 0.183 CTIO V 0.5517 2.682 0.113 3.24 0.137 CTIO R 0.652 2.119 0.09 2.634 0.111 CTIO I 0.8007 1.516 0.064 1.962 0.083 DSS-II g 0.4621 3.381 0.143 3.907 0.165 DSS-II r 0.6546 2.088 0.088 2.649 0.112 DSS-II i 0.8111 1.487 0.063 1.893 0.08 SDSS u 0.3587 4.239 0.179 5.155 0.218 SDSS g 0.4717 3.303 0.14 3.793 0.16 ... ... ... ... ... ... UKIRT K 2.19 0.302 0.013 0.367 0.016 2MASS J 1.23 0.723 0.031 0.937 0.04 2MASS H 1.64 0.46 0.019 0.591 0.025 2MASS Ks 2.16 0.31 0.013 0.382 0.016 IRAC-1 3.52 0.178 0.008 0.22 0.009 IRAC-2 4.46 0.148 0.006 0.183 0.008 IRAC-3 5.66 0.13 0.005 0.162 0.007 IRAC-4 7.68 0.122 0.005 0.151 0.006 WISE-1 3.32 0.189 0.008 0.234 0.01 WISE-2 4.57 0.146 0.006 0.18 0.008 Length = 25 rows Get other query details ----------------------- This fetches in a `~astropy.table.Table` other additional details that may be returned in the query results. For instance additional details in the three sections - ``ebv``, ``100um`` and ``temperature`` as mentioned earlier and an additional section ``location`` may be fetched using the ``section`` keyword argument. If on the other hand, ``section`` is missing then the complete table with all the four sections will be returned. .. doctest-remote-data:: >>> from astroquery.ipac.irsa.irsa_dust import IrsaDust >>> table = IrsaDust.get_query_table('2MASXJ23045666+1219223') # get the whole table >>> print(table) RA Dec coord sys regSize ... temp mean temp std temp max temp min deg deg deg ... --------- -------- --------- ------- ... --------- -------- -------- -------- 346.23608 12.32286 equ J2000 5.0 ... 17.0721 0.0345 17.1189 17.0152 >>> table_ebv = IrsaDust.get_query_table('2MASXJ23045666+1219223', section='ebv') # get only one section >>> print(table_ebv) ext desc ... ext SFD min ... ---------------- ... ----------- E(B-V) Reddening ... 0.1099 Troubleshooting =============== If you are repeatedly getting failed queries, or bad/out-of-date results, try clearing your cache: .. code-block:: python >>> from astroquery.ipac.irsa.irsa_dust import IrsaDust >>> IrsaDust.clear_cache() If this function is unavailable, upgrade your version of astroquery. The ``clear_cache`` function was introduced in version 0.4.7.dev8479. Reference/API ============= .. automodapi:: astroquery.ipac.irsa.irsa_dust :no-inheritance-diagram: .. _IRSA Dust Extinction Service: http://irsa.ipac.caltech.edu/applications/DUST/index.html .. _IRSA DUST coordinates description page: http://irsa.ipac.caltech.edu/applications/DUST/docs/coordinate.html