Measuring Resolutions (2023) - Revision history

Rebull at 15:51, 16 May 2023

2023-05-16T15:51:54Z

Rebull at 21:31, 23 April 2023

2023-04-23T21:31:39Z

Rebull at 21:30, 23 April 2023

2023-04-23T21:30:59Z

Rebull at 21:30, 23 April 2023

2023-04-23T21:30:14Z

Rebull: /* Getting started on filling out that table */

2023-04-23T21:26:30Z

Getting started on filling out that table

Rebull at 21:25, 23 April 2023

2023-04-23T21:25:11Z

Rebull at 21:24, 23 April 2023

2023-04-23T21:24:40Z

Rebull at 21:23, 23 April 2023

2023-04-23T21:23:32Z

Rebull: /* Getting started on filling out that table */

2023-04-23T15:51:53Z

Getting started on filling out that table

Rebull at 15:50, 23 April 2023

2023-04-23T15:50:04Z

@@ Line 30: / Line 30: @@
 | Herschel/SPIRE || 250-500 um || || || IRSA Viewer
 |-
-| Akari/IRC || 9-18 um || || ''(no images released so can't do this)'' || (aren't accessible; ones in IRSA tools are FIS, not IRC)
+| Akari/IRC || 9-18 um || ''(~5 arcsec; FIS is 1-1.5 ARCMIN)'' || ''(no images released so can't do this)'' || (aren't accessible; ones in IRSA tools are FIS, not IRC)
 |-
-| MSX || 7.8-21 um || || ''(varies a lot over the bands; you can just pick 1 or 2)'' || IRSA Viewer
+| MSX || 7.8-21 um || ''(harder than i thought it would be; it's 12-20 arcsec)'' || ''(varies a lot over the bands; you can just pick 1 or 2)'' || IRSA Viewer
 |-
 | IRAS || 12-100 um || || || Finder Chart or IRSA Viewer

@@ Line 30: / Line 30: @@
 | Herschel/SPIRE || 250-500 um || || || IRSA Viewer
 |-
-| Akari/IRC || 9-18 um || || ''(no images released so can't do this)'' || (aren't accessible)
+| Akari/IRC || 9-18 um || || ''(no images released so can't do this)'' || (aren't accessible; ones in IRSA tools are FIS, not IRC)
 |-
 | MSX || 7.8-21 um || || ''(varies a lot over the bands; you can just pick 1 or 2)'' || IRSA Viewer

@@ Line 10: / Line 10: @@
 {| class="wikitable"
 |-
-! Data source !! Wavelengths !! Reported spatial resolution !! Empirical spatial resolution !! (Where you find the data)
+! Data source !! Wavelengths !! Reported spatial resolution !! Empirical spatial resolution !! Where you find the images
 |-
 | PanSTARRS || 0.48-0.96 um || || || https://ps1images.stsci.edu/cgi-bin/ps1cutouts
@@ Line 16: / Line 16: @@
 | IPHAS || 0.62-0.77 um || || || https://www.iphas.org/images/
 |-
-| Gaia || 0.622-0.777 um || || ''(no images released so can't do this)'' || (doesn't exist)
+| Gaia || 0.622-0.777 um || || ''(no images released so can't do this)'' || (don't exist)
 |-
 | 2MASS || 1.2-2.2 um || || || Finder Chart or IRSA Viewer (use 6 deg img if IRSA Viewer)
@@ Line 30: / Line 30: @@
 | Herschel/SPIRE || 250-500 um || || || IRSA Viewer
 |-
-| Akari/IRC || 9-18 um || || ''(no images released so can't do this)'' || (doesn't exist)
+| Akari/IRC || 9-18 um || || ''(no images released so can't do this)'' || (aren't accessible)
 |-
 | MSX || 7.8-21 um || || ''(varies a lot over the bands; you can just pick 1 or 2)'' || IRSA Viewer

@@ Line 10: / Line 10: @@
 {| class="wikitable"
 |-
-! Data source !! Wavelengths !! Reported spatial resolution !! Empirical spatial resolution
+! Data source !! Wavelengths !! Reported spatial resolution !! Empirical spatial resolution !! (Where you find the data)
 |-
-| PanSTARRS || 0.48-0.96 um || ||
+| PanSTARRS || 0.48-0.96 um || || || https://ps1images.stsci.edu/cgi-bin/ps1cutouts
 |-
-| IPHAS || 0.62-0.77 um || ||
+| IPHAS || 0.62-0.77 um || || || https://www.iphas.org/images/
 |-
-| Gaia || 0.622-0.777 um || || ''(no images released so can't do this)''
+| Gaia || 0.622-0.777 um || || ''(no images released so can't do this)'' || (doesn't exist)
 |-
-| 2MASS || 1.2-2.2 um || ||
+| 2MASS || 1.2-2.2 um || || || Finder Chart or IRSA Viewer (use 6 deg img if IRSA Viewer)
 |-
-| WISE || 3.5-22 um || ||
+| WISE || 3.5-22 um || || || Finder Chart or IRSA Viewer
 |-
-| Spitzer/IRAC || 3.5-8 um || ||
+| Spitzer/IRAC || 3.5-8 um || || || Finder Chart or IRSA Viewer, but some data sets only IRSA Viewer
 |-
-| Spitzer/MIPS || 24 um || ||
+| Spitzer/MIPS || 24 um || || || Finder Chart or IRSA Viewer
 |-
-| Herschel/PACS || 70-160 um || ||
+| Herschel/PACS || 70-160 um || || || IRSA Viewer
 |-
-| Herschel/SPIRE || 250-500 um || ||
+| Herschel/SPIRE || 250-500 um || || || IRSA Viewer
 |-
-| Akari/IRC || 9-18 um || || ''(no images released so can't do this)''
+| Akari/IRC || 9-18 um || || ''(no images released so can't do this)'' || (doesn't exist)
 |-
-| MSX || 7.8-21 um || || ''(varies a lot over the bands; you can just pick 1 or 2)''
+| MSX || 7.8-21 um || || ''(varies a lot over the bands; you can just pick 1 or 2)'' || IRSA Viewer
 |-
-| IRAS || 12-100 um || ||
+| IRAS || 12-100 um || || || Finder Chart or IRSA Viewer
 |}

← Older revision		Revision as of 21:26, 23 April 2023
Line 59:		Line 59:
	Column four means you need to start pulling images. Finder Chart. IRSA Viewer. Sh 2-192 and Sh 2-187 over 20 arcminutes.		Column four means you need to start pulling images. Finder Chart. IRSA Viewer. Sh 2-192 and Sh 2-187 over 20 arcminutes.

−	What is the size of each pixel for ~~each survey~~? (Option #1 to do this: Make the image big enough in your view of it that you can see pixels, and measure the size of it using ruler tools (not a real ruler). Option #2 to do this: look in the FITS header and find a useful keyword.) Try at least one image from each of the surveys.	+	What is the size of each pixel for at least the three core data sets (2MASS, Spitzer/IRAC, WISE)? (Option #1 to do this: Make the image big enough in your view of it that you can see pixels, and measure the size of it using ruler tools (not a real ruler). Option #2 to do this: look in the FITS header and find a useful keyword.) Try at least one image from each of the surveys.

@@ Line 37: / Line 37: @@
 |}
-* Minimum expectations: look up the reported resolution for, and empirically find the spatial resolution of, 2MASS, Spitzer/IRAC, and WISE. (columns 3 and 4 for for three rows), and attempt the questions in "Backing out to the bigger picture"
+* Minimum expectations: look up the reported resolution for, and empirically find the spatial resolution of, 2MASS, Spitzer/IRAC, and WISE (columns 3 and 4 for for three rows), and attempt the questions in "Backing out to the bigger picture"
 * Meets expectations: look up the reported resolution for everything (all of column 3) and empirically find the spatial resolution of 2MASS, Spitzer/IRAC, and WISE (column four, three rows), and answer the questions in "Backing out to the bigger picture"
 * Exceeds expectations: fill out as many cells as you can, and answer the questions in "Backing out to the bigger picture", and come up with some questions of your own! :)

@@ Line 1: / Line 1: @@
 =Goals=
 Since spatial resolution issues are going to be important for our work, let’s explore what spatial resolutions we have in our data. The first goal of this worksheet is to fill out the following table. The second goal is to apply that knowledge to two of our objects (see below). I have made a movie with sort of QuickStart guidance https://youtu.be/Y5DEo6amN44 but it is totally silent because I’m in my mom’s room at the nursing facility and she is dozing.
 {| class="wikitable"
@@ Line 37: / Line 41: @@
 * Exceeds expectations: fill out as many cells as you can
-'''Read the stuff below before you try to fill out this table!'''
+'''Read the entire page below before you try to fill out this table!'''
 =Background motivation=

@@ Line 51: / Line 51: @@
 In order to fill out that table, you need to explore both documentation and the images themselves.
-Column three is all documentation, most of which can be found at IRSA. Google!! :) "spatial resolution of 2MASS", etc. You should be finding numbers in units of arcseconds.
+Column three is all documentation, most of which can be found at IRSA. Google!! :) "spatial resolution of 2MASS", etc. You should be finding numbers in units of arcseconds. (arcseconds per pixel to be precise!) If you are finding numbers in degrees or arcMINUTES per pixel, convert the units! 60 arcseconds to an arcminute, and 60 arcminutes to a degree.
 Column four means you need to start pulling images. Finder Chart. IRSA Viewer. Sh 2-192 and Sh 2-187 over 20 arcminutes.
@@ Line 58: / Line 58: @@
 For at least one frame from each of the surveys you want to work with, go and measure the sizes of 3 to 5 ‘typical’ isolated point sources in these images. That's your empirical spatial resolution for the table above. Changing the color table/stretch is useful for telling if the image is slightly asymmetric (implying a barely resolved companion) or saturated or other things; it is also going to change the apparent size of the sources! (It is going to be hard to find 'typical' in IRAS if you want to work with those data; do what you can.)
 =Backing out to the bigger picture again=