Working with the IC 417 data - Revision history

Rebull at 01:50, 18 June 2015

2015-06-18T01:50:05Z

Rebull: /* Assessing SEDs */

2015-06-16T22:09:42Z

Assessing SEDs

Rebull at 21:46, 16 June 2015

2015-06-16T21:46:24Z

Rebull at 21:43, 16 June 2015

2015-06-16T21:43:56Z

Rebull: /* Assessing SEDs */

2015-06-16T20:46:51Z

Assessing SEDs

Rebull: /* Assessing SEDs */

2015-06-16T17:42:42Z

Assessing SEDs

Rebull: /* Data Tables (part 2) */

2015-06-15T22:50:28Z

Data Tables (part 2)

Rebull at 20:18, 9 June 2015

2015-06-09T20:18:32Z

Show changes

Rebull: /* CMDs and CCDs, part 2 */

2015-06-09T16:47:10Z

CMDs and CCDs, part 2

Rebull: /* CMDs and CCDs, part 2 */

2015-06-09T16:46:45Z

CMDs and CCDs, part 2

@@ Line 251: / Line 251: @@
 =Assessing SEDs =
-<font color="green">DO THIS.</font>
+<font color="green"><strike>DO THIS!</strike></font> <font color="red">FIRST PASS DONE! Needs a second pass...</font>
 '''Why?''' Now that you've made at least one SED, you know how to do this. We will wave our magic wand and assume you can do it, given enough time, for all 200 sources of interest. With some help from me, then, to jump that barrier in the limited time we have here at Caltech, we need to next look at the SEDs from all 200 sources of interest with a critical eye. They will not all be clean and neat. We will need to fold in information learned from the image assessments.
@@ Line 277: / Line 277: @@
 =CMDs and CCDs, part 2=
-<font color="green">DO THIS.</font>
+<font color="green"><strike>DO THIS!</strike></font> <font color="red">DONE, at least with the results of the first pass above. </font>
 '''Why?''' We have now weeded the objects in which we are interested to get rid of the things that really have problems. We now have a shortlist of things that we are starting to believe may be YSOs. We have a lot of ancillary data, and we can do more checking using these data to see how confident we are in these objects, so that we can refine our list of true YSO candidates vs. junk.
@@ Line 293: / Line 293: @@
 =Analyzing SEDs=
-<font color="green">DO THIS (now if we can, but we may skip this).</font>
+<font color="green">DO THIS.</font>
 '''Why?''' There are empirically defined groupings of SED shapes -- Class 0s and Class Is are the most embedded (presumably youngest); Class IIIs are the least embedded (presumably oldest). How do our new YSOs compare to this? Have we mostly found Class IIs?
@@ Line 312: / Line 312: @@
 =Going back to check the literature=
-<font color="green">DO THIS (now if we can).</font>
+<font color="green">DO THIS (if we can).</font>
 '''Why?''' We did a pretty thorough literature check a few months ago, but (a) it's not infallible, and (b) astronomers have kept on publishing since then. For each of the objects we are asserting are new YSOs, we should go back and check the literature to be sure, e.g., that someone else didn't just publish a spectrum that says its a carbon star (meaning, not a young star).
@@ Line 337: / Line 337: @@
 =Putting this in context a little: Science=
-<font color="green">DO THIS (now if we can).</font>
+<font color="green">DO THIS.</font>
 '''Why?''' We've been doing a lot of nitty gritty work with the data. But now it's time to back up and look at the big picture again.
@@ Line 349: / Line 349: @@
 =Writing it up!=
-<font color="green">DO THIS (now if we can).</font>
+<font color="green">DO THIS.</font>
 '''Why?''' Now that we have completed a lot of work, we need to tell other people what we did, and what we found out about the Universe that no one else knows yet.

@@ Line 273: / Line 273: @@
 #Accreting young stars, or stars that are rotating quickly (often because they are young) are bright in Halpha. If Halpha is much above the rest of the SED, that's OK, and in fact a GOOD THING, because that is more evidence that the star is young. That is why the Halpha point is colored red in my SEDs.
 #Remember that in the context of IR excesses, 2 to 22 microns is the most important. There may be wackiness in the optical, and it may matter (especially if there is a mismatch between sources) but if UKIDSS J doesn't match with 2MASS J, that's less of an issue than if, say, IRAC 3.6 microns doesn't match with WISE 3.4 microns, because we care more about the IR side of the SED.
-#Black triangles = optical (Jose et al. UBVI or IPHAS ri). Red triangle = Halpha (which means that bright is ok). Black diamonds = 2MASS. Green squares = UKIDSS. black stars = WISE. blue circles = IRAC.
+#Black triangles = IPHAS ri. Black plus signs = Jose et al. UBVI Red triangle = Halpha (which means that bright is ok). Black diamonds = 2MASS. Green squares = UKIDSS. black stars = WISE. blue circles = IRAC.
 =CMDs and CCDs, part 2=

@@ Line 44: / Line 44: @@
 =Investigating the big mosaics =
-<strike><font color="green">DO THIS!</font></strike> <font color="red">DONE! </font>
+<font color="green"><strike>DO THIS!</strike></font> <font color="red">DONE! </font>
 '''Why?''' There is astrophysics in understanding what is bright/faint in each band. Spatial resolution is going to play a role downstream.
@@ Line 107: / Line 107: @@
 =Previously identified sources=
-<font color="red">PARTIALLY DONE.</font> <font color="green">DO THE PART WITH THE CLUSTERS.</font>
+<font color="red">NOW COMPLETELY DONE.</font>
 '''Why?''' Others have gone before us, and it pays to learn from them rather than reinvent the wheel.
@@ Line 146: / Line 146: @@
 =Data Tables (part 1) and Color-Color and Color-Magnitude Diagrams (part 1)=
-<font color="green">DO THIS.</font>
+<font color="green"><strike>DO THIS!</strike></font> <font color="red">DONE! </font>
 '''Why?''' Xavier found sources with YSO-like colors by making a bunch of CMDs and CCDs and selecting objects from these diagrams. It behooves us to get a sense of what he did. (And, we will need to make more CMDs/CCDs downstream.)
@@ Line 192: / Line 192: @@
 =Data Tables (part 2)=
-<font color="green">DO THIS.</font>
+<font color="green"><strike>DO THIS!</strike></font> <font color="red">DONE! </font>
 '''Why?''' For each of the sources we care about, we need to make SEDs so that we can decide if these sources have IR excesses. We also need to make CMDs/CCDs too. Getting data tables into Excel is the first step in that process.
@@ Line 219: / Line 219: @@
 =Making SEDs =
-<font color="green">DO THIS.</font>
+<font color="green"><strike>DO THIS!</strike></font> <font color="red">DONE! </font>
 '''Why?''' For each of the sources we care about, we need to make SEDs so that we can decide if these sources have IR excesses. Let's do this!

@@ Line 21: / Line 21: @@
 =Obtaining the imaging data=
-<font color="red">DONE </font> <font color="green">but be sure you have the files you need!</font>
+<font color="red">DONE </font> (but be sure you have the files you need!)
 '''Why?''' Need to figure out what data are in this region from which we might obtain photometry (=quantitative measures of brightness of objects) to use to look for IR excess sources.
@@ Line 44: / Line 44: @@
 =Investigating the big mosaics =
-<font color="green">DO THIS!</font>
+<strike><font color="green">DO THIS!</font></strike> <font color="red">DONE! </font>
 '''Why?''' There is astrophysics in understanding what is bright/faint in each band. Spatial resolution is going to play a role downstream.

@@ Line 273: / Line 273: @@
 #Accreting young stars, or stars that are rotating quickly (often because they are young) are bright in Halpha. If Halpha is much above the rest of the SED, that's OK, and in fact a GOOD THING, because that is more evidence that the star is young. That is why the Halpha point is colored red in my SEDs.
 #Remember that in the context of IR excesses, 2 to 22 microns is the most important. There may be wackiness in the optical, and it may matter (especially if there is a mismatch between sources) but if UKIDSS J doesn't match with 2MASS J, that's less of an issue than if, say, IRAC 3.6 microns doesn't match with WISE 3.4 microns, because we care more about the IR side of the SED.
 =CMDs and CCDs, part 2=

@@ Line 265: / Line 265: @@
 More mechanics of process:
-Get the file with all the SEDs in it from the Box drive. We will do the first 9 as a group. Then you should work as a 2-person team and go through each of the objects you're assigned and make notes about what you see.  There is a blank Excel file in the Box drive for you to use, or maybe we should use a Google doc to collect responses.   (Ideally would have 6 teams of 2, and have at least 2 teams do each source. For 200 sources, that's at absolute minimum ~30 per team to have just one team per object.)
+Get the file with all the SEDs in it from the Box drive. We will do the first 9 as a group. Then you should work as a 2 or 3-person team and go through each of the objects you're assigned and make notes about what you see.  There is a blank Excel file in the Box drive for you to use, or maybe we should use a Google doc to collect responses.   (Ideally would have at least 5 teams of 2 or 3, and have at least 2 teams do each source. For 200 sources, that's at absolute minimum ~30 per team to have just one team per object.)
 '''Questions''' to think about for each source: Does it look like a YSO SED? Does it look like the data weren't tied to the correct source or there were spatial resolution problems? Discuss with your partner about whether or not you believe each source, and why. Do you believe each point in the SED? If not, why not? Don't forget to compare your notes on SEDs with notes on images (e.g., if you decide it is "iffy" in images AND "iffy" in SEDs, chances are excellent that it is not a good candidate).  Keep good notes on this!
@@ Line 273: / Line 273: @@
 #Accreting young stars, or stars that are rotating quickly (often because they are young) are bright in Halpha. If Halpha is much above the rest of the SED, that's OK, and in fact a GOOD THING, because that is more evidence that the star is young. That is why the Halpha point is colored red in my SEDs.
 #Remember that in the context of IR excesses, 2 to 22 microns is the most important. There may be wackiness in the optical, and it may matter (especially if there is a mismatch between sources) but if UKIDSS J doesn't match with 2MASS J, that's less of an issue than if, say, IRAC 3.6 microns doesn't match with WISE 3.4 microns, because we care more about the IR side of the SED.
 =CMDs and CCDs, part 2=

@@ Line 194: / Line 194: @@
 <font color="green">DO THIS.</font>
-'''Why?''' For each of the sources we care about, we need to make SEDs so that we can decide if these sources have IR excesses. Getting data tables into Excel is the first step in that process.
+'''Why?''' For each of the sources we care about, we need to make SEDs so that we can decide if these sources have IR excesses. We also need to make CMDs/CCDs too. Getting data tables into Excel is the first step in that process.
 '''Relevant links for reference''': [http://www.youtube.com/watch?v=nCJ3ctOGvNk YouTube video] on what tbl files are, how to access them, and specifically how to import tbl files into xls. (10min)
-'''Process''': Get "workingcatalog-interesting" into Excel, with all columns divided appropriately.
+'''Process''': Get "workingcatalog-interesting" and "workingcatalog-all" into Excel, with all columns divided appropriately.
 '''Hints and Advice''':

@@ Line 288: / Line 288: @@
 ''We will reassess on the fly, but most likely, we will make one plot together and then we will wave our magic wand and assume you can make these plots, given enough time, for our entire catalog, and highlight the sources of interest. With some help from me, again, I will make a pile of CMDs and CCDs and we will talk about them as a group.''
-'''Process''':  By this point you (we) should have a list of things that have survived tests.  You (I) can make a wide variety of CMDs and CCDs with these objects highlighted. We will then go through each of them and decide what to believe.
+'''Process''':  By this point you should have a list of things that have survived tests.  You can make a wide variety of CMDs and CCDs with these objects highlighted. We will then go through each of them and decide what to believe.
 Make a WISE color-mag diagram such as one of the ones you made earlier, but this time do it in Excel. Overplot the survivors of the image and SED tests on this diagram. Where do they fall? Are they where you expect them to be? You may wish to plot the WISE data for *everything* and then just overplot the interesting ones. Or you may wish to just plot the interesting ones, and look at WISE plots for comparison. Tag any of the survivors as less likely if they aren't where they should be.

@@ Line 286: / Line 286: @@
 '''Why?''' We have now weeded the objects in which we are interested to get rid of the things that really have problems. We now have a shortlist of things that we are starting to believe may be YSOs. We have a lot of ancillary data, and we can do more checking using these data to see how confident we are in these objects, so that we can refine our list of true YSO candidates vs. junk.
-''We will reassess on the fly, but most likely, we will wave our magic wand and assume you can make these plots, given enough time, for our entire catalog, and highlight the sources of interest. With some help from me, again, I will make a pile of CMDs and CCDs and we will talk about them as a group.''
+''We will reassess on the fly, but most likely, we will make one plot together and then we will wave our magic wand and assume you can make these plots, given enough time, for our entire catalog, and highlight the sources of interest. With some help from me, again, I will make a pile of CMDs and CCDs and we will talk about them as a group.''
 '''Process''':  By this point you (we) should have a list of things that have survived tests.  You (I) can make a wide variety of CMDs and CCDs with these objects highlighted. We will then go through each of them and decide what to believe.
@@ Line 294: / Line 294: @@
 Repeat for 2MASS color-color and color-mag diagrams.  Don't forget about reddening. Are the sources where you expect them to be?
 We have optical data for a lot of these objects. You can make several different possible optical CMDs and see if the "literature YSOs (that may or may not have a disk)" and "still surviving as new YSO candidates" fall in the 'right place' in these diagrams. For context, you could take all the optical data we have for all the objects in the region and plot r vs r-i from the IPHAS data. Overplot the survivors on this diagram. Are they where they should be (above the ZAMS)? Do this again, but for r-Halpha vs. r-i.   Are the survivors where they should be (substantially above the unreddened main sequence locus)?
 =Analyzing SEDs=