# SkyViewClass¶

class astroquery.skyview.SkyViewClass[source]

Attributes Summary

Methods Summary

 get_image_list(position, survey[, …]) Query the SkyView service, download the FITS file that will be found and return a generator over the local paths to the downloaded FITS files. get_images(position, survey[, coordinates, …]) Query the SkyView service, download the FITS file that will be found and return a generator over the local paths to the downloaded FITS files. get_images_async(position, survey[, …]) Query the SkyView service, download the FITS file that will be found and return a generator over the local paths to the downloaded FITS files. list_surveys() Print out a formatted version of the survey dict

Attributes Documentation

URL = 'http://skyview.gsfc.nasa.gov/current/cgi/basicform.pl'
survey_dict

Methods Documentation

get_image_list(position, survey, coordinates=None, projection=None, pixels=None, scaling=None, sampler=None, resolver=None, deedger=None, lut=None, grid=None, gridlabels=None, radius=None, width=None, height=None, cache=True)[source]

Query the SkyView service, download the FITS file that will be found and return a generator over the local paths to the downloaded FITS files.

Note that the files will be downloaded when the generator will be exhausted, i.e. just calling this method alone without iterating over the result won’t issue a connection to the SkyView server.

Parameters: position : str Determines the center of the field to be retrieved. Both coordinates (also equatorial ones) and object names are supported. Object names are converted to coordinates via the SIMBAD or NED name resolver. See the reference for more info on the supported syntax for coordinates. survey : str or list of str Select data from one or more surveys. The number of surveys determines the number of resulting file downloads. Passing a list with just one string has the same effect as passing this string directly. coordinates : str Choose among common equatorial, galactic and ecliptic coordinate systems ("J2000", "B1950", "Galactic", "E2000", "ICRS") or pass a custom string. projection : str Choose among the map projections (the value in parentheses denotes the string to be passed): Gnomonic (Tan), default value good for small regions Rectangular (Car) simplest projection Aitoff (Ait) Hammer-Aitoff, equal area projection good for all sky maps Orthographic (Sin) Projection often used in interferometry Zenith Equal Area (Zea) equal area, azimuthal projection COBE Spherical Cube (Csc) Used in COBE data Arc (Arc) Similar to Zea but not equal-area pixels : str Selects the pixel dimensions of the image to be produced. A scalar value or a pair of values separated by comma may be given. If the value is a scalar the number of width and height of the image will be the same. By default a 300x300 image is produced. scaling : str Selects the transformation between pixel intensity and intensity on the displayed image. The supported values are: "Log", "Sqrt", "Linear", "HistEq", "LogLog". sampler : str The sampling algorithm determines how the data requested will be resampled so that it can be displayed. resolver : str The name resolver allows to choose a name resolver to use when looking up a name which was passed in the position parameter (as opposed to a numeric coordinate value). The default choice is to call the SIMBAD name resolver first and then the NED name resolver if the SIMBAD search fails. deedger : str When multiple input images with different backgrounds are resampled the edges between the images may be apparent because of the background shift. This parameter makes it possible to attempt to minimize these edges by applying a de-edging algorithm. The user can elect to choose the default given for that survey, to turn de-edging off, or to use the default de-edging algorithm. The supported values are: "_skip_" to use the survey default, "skyview.process.Deedger" (for enabling de-edging), and "null" to disable. lut : str Choose from the color table selections to display the data in false color. grid : bool overlay a coordinate grid on the image if True gridlabels : bool annotate the grid with coordinates positions if True radius : Quantity or None The radius of the specified field. Overrides width and height. width : Quantity or None The width of the specified field. Must be specified with height. height : Quantity or None The height of the specified field. Must be specified with width. list of image urls

References

Examples

>>> SkyView().get_image_list(position='Eta Carinae',
...                          survey=['Fermi 5', 'HRI', 'DSS'])
[u'http://skyview.gsfc.nasa.gov/tempspace/fits/skv6183161285798_1.fits',
u'http://skyview.gsfc.nasa.gov/tempspace/fits/skv6183161285798_2.fits',
u'http://skyview.gsfc.nasa.gov/tempspace/fits/skv6183161285798_3.fits']

get_images(position, survey, coordinates=None, projection=None, pixels=None, scaling=None, sampler=None, resolver=None, deedger=None, lut=None, grid=None, gridlabels=None, radius=None, height=None, width=None, cache=True, show_progress=True)[source]

Query the SkyView service, download the FITS file that will be found and return a generator over the local paths to the downloaded FITS files.

Note that the files will be downloaded when the generator will be exhausted, i.e. just calling this method alone without iterating over the result won’t issue a connection to the SkyView server.

Parameters: position : str Determines the center of the field to be retrieved. Both coordinates (also equatorial ones) and object names are supported. Object names are converted to coordinates via the SIMBAD or NED name resolver. See the reference for more info on the supported syntax for coordinates. survey : str or list of str Select data from one or more surveys. The number of surveys determines the number of resulting file downloads. Passing a list with just one string has the same effect as passing this string directly. coordinates : str Choose among common equatorial, galactic and ecliptic coordinate systems ("J2000", "B1950", "Galactic", "E2000", "ICRS") or pass a custom string. projection : str Choose among the map projections (the value in parentheses denotes the string to be passed): Gnomonic (Tan), default value good for small regions Rectangular (Car) simplest projection Aitoff (Ait) Hammer-Aitoff, equal area projection good for all sky maps Orthographic (Sin) Projection often used in interferometry Zenith Equal Area (Zea) equal area, azimuthal projection COBE Spherical Cube (Csc) Used in COBE data Arc (Arc) Similar to Zea but not equal-area pixels : str Selects the pixel dimensions of the image to be produced. A scalar value or a pair of values separated by comma may be given. If the value is a scalar the number of width and height of the image will be the same. By default a 300x300 image is produced. scaling : str Selects the transformation between pixel intensity and intensity on the displayed image. The supported values are: "Log", "Sqrt", "Linear", "HistEq", "LogLog". sampler : str The sampling algorithm determines how the data requested will be resampled so that it can be displayed. resolver : str The name resolver allows to choose a name resolver to use when looking up a name which was passed in the position parameter (as opposed to a numeric coordinate value). The default choice is to call the SIMBAD name resolver first and then the NED name resolver if the SIMBAD search fails. deedger : str When multiple input images with different backgrounds are resampled the edges between the images may be apparent because of the background shift. This parameter makes it possible to attempt to minimize these edges by applying a de-edging algorithm. The user can elect to choose the default given for that survey, to turn de-edging off, or to use the default de-edging algorithm. The supported values are: "_skip_" to use the survey default, "skyview.process.Deedger" (for enabling de-edging), and "null" to disable. lut : str Choose from the color table selections to display the data in false color. grid : bool overlay a coordinate grid on the image if True gridlabels : bool annotate the grid with coordinates positions if True radius : Quantity or None The radius of the specified field. Overrides width and height. width : Quantity or None The width of the specified field. Must be specified with height. height : Quantity or None The height of the specified field. Must be specified with width. A list of ~astropy.io.fits.HDUList objects.

References

Examples

>>> sv = SkyView()
>>> paths = sv.get_images(position='Eta Carinae',
...                       survey=['Fermi 5', 'HRI', 'DSS'])
>>> for path in paths:
...     print(' new file:', path)

get_images_async(position, survey, coordinates=None, projection=None, pixels=None, scaling=None, sampler=None, resolver=None, deedger=None, lut=None, grid=None, gridlabels=None, radius=None, height=None, width=None, cache=True, show_progress=True)[source]

Query the SkyView service, download the FITS file that will be found and return a generator over the local paths to the downloaded FITS files.

Note that the files will be downloaded when the generator will be exhausted, i.e. just calling this method alone without iterating over the result won’t issue a connection to the SkyView server.

Parameters: position : str Determines the center of the field to be retrieved. Both coordinates (also equatorial ones) and object names are supported. Object names are converted to coordinates via the SIMBAD or NED name resolver. See the reference for more info on the supported syntax for coordinates. survey : str or list of str Select data from one or more surveys. The number of surveys determines the number of resulting file downloads. Passing a list with just one string has the same effect as passing this string directly. coordinates : str Choose among common equatorial, galactic and ecliptic coordinate systems ("J2000", "B1950", "Galactic", "E2000", "ICRS") or pass a custom string. projection : str Choose among the map projections (the value in parentheses denotes the string to be passed): Gnomonic (Tan), default value good for small regions Rectangular (Car) simplest projection Aitoff (Ait) Hammer-Aitoff, equal area projection good for all sky maps Orthographic (Sin) Projection often used in interferometry Zenith Equal Area (Zea) equal area, azimuthal projection COBE Spherical Cube (Csc) Used in COBE data Arc (Arc) Similar to Zea but not equal-area pixels : str Selects the pixel dimensions of the image to be produced. A scalar value or a pair of values separated by comma may be given. If the value is a scalar the number of width and height of the image will be the same. By default a 300x300 image is produced. scaling : str Selects the transformation between pixel intensity and intensity on the displayed image. The supported values are: "Log", "Sqrt", "Linear", "HistEq", "LogLog". sampler : str The sampling algorithm determines how the data requested will be resampled so that it can be displayed. resolver : str The name resolver allows to choose a name resolver to use when looking up a name which was passed in the position parameter (as opposed to a numeric coordinate value). The default choice is to call the SIMBAD name resolver first and then the NED name resolver if the SIMBAD search fails. deedger : str When multiple input images with different backgrounds are resampled the edges between the images may be apparent because of the background shift. This parameter makes it possible to attempt to minimize these edges by applying a de-edging algorithm. The user can elect to choose the default given for that survey, to turn de-edging off, or to use the default de-edging algorithm. The supported values are: "_skip_" to use the survey default, "skyview.process.Deedger" (for enabling de-edging), and "null" to disable. lut : str Choose from the color table selections to display the data in false color. grid : bool overlay a coordinate grid on the image if True gridlabels : bool annotate the grid with coordinates positions if True radius : Quantity or None The radius of the specified field. Overrides width and height. width : Quantity or None The width of the specified field. Must be specified with height. height : Quantity or None The height of the specified field. Must be specified with width. A list of context-managers that yield readable file-like objects

References

Examples

>>> sv = SkyView()
>>> paths = sv.get_images(position='Eta Carinae',
...                       survey=['Fermi 5', 'HRI', 'DSS'])
>>> for path in paths:
...     print(' new file:', path)

list_surveys()[source]

Print out a formatted version of the survey dict