The two fits plotted over each other look like this:



Still attempting to figure out how to plot y error bars....

For 0931, one off-chip source located at 143.04074, 36.50115, had a high x-ray flux, so we took a closer look at it. We are investigating to see if it falls under the category of an XBONG.

Our source is slightly extended (I'm trying to extract a radial profile, but am having trouble with the syntax in bash..) It's chandra counts in the 0.5-2.0keV range were 165, and in the 5-10keV range were 65 (230 over the whole range). It has a redshift of z=0.15, and when assuming a powerlaw dependence and a photon index of 1.9 (characteristic of x-bongs, for which gamma ranges between 1.6-2.4, this leads to an x-ray luminosity of approx. 2.2e43 erg/s.

The source has a ROSAT counterpart cataloged, with a countrate of 4.78e-2+/-1.38, which using WEBPIMMS for ROSAT PSPC, leads to a luminosity of 2.075*10^43erg/s.

We decided to extract spectra from the chandra source, using the ciao routine specextract.

I attempted to fit the spectra based on the discussion of similar sources by Civano et al. 2007, in which they fit a mekal model with the lower energies of the spectra, and then a powerlaw for the higher energies. I as of yet haven't figured out how to fit different source models in different regimes, but here is an image of the data in the 0.5-10.0keV range fit first with the xsmekal source model, parametrized only by the redshift and with "switch"=0, and with an absorbed powerlaw, with gamma=1.6 and nH of 0.0142e-22.

The mekal fit looks as follows (unsure of why it appears to fall off and not intersect the high energy data points, I think this is something weird that happens from the log_scale command..)


And the powerlaw:


The statistics from these fits over the 0.5-10keV range are as follows:
mekal, rstat = 0.632163888096
powlaw, rstat = 0.619105037196

The next step is to get the y errors, and overplot or consolidate in one plot the two fits, which I have had no luck with so far...

The colors of the sources close to the SNR are:

275.23312 -14.32476 (the further source)
IR:

closest source was 2.039001" away , at RA: 275.233684, DEC: -14.324909, with theses colors: j_mag:12.093, h_m: 11.612, k_mag: 11.402, and j-h=0.4810, h-k=0.2100, j-k=0.6910
errors were: j_msigcom:0.023, j_snr:323.8, h_msigcom:0.028, h_snr: 94.2,k_msigcom: 0.030, k_snr: 91.3- snr's are insanely high, unfortunately, not sure if this debunks any of this....
FLAGS: ph_qual: AAA, rd_flg:222, bl_flg: 111, cc_flg:000

optical:
closest source was 2.052775", at RA: 275.233659, DEC:-14.324989, with these colors, b1_mag: 15.48, r1_mag: 13.54,
errors: e_ra: 82, e_dec:69, there were no flags


For 275.23763 -14.33405 (the source closer, to the right side of the snr flux peak),
In the IR:

There were two sources found within a radius of 5"
The closest was 1.079200" away, RA: 275.237796, DEC: -14.334303, with these colors: j_mag:16.008, h_m: 14.235, k_mag: 12.635, j-h=1.7730, h-k=1.600, j-k=3.37300
errors were: j_msigcom:0.096, j_snr:8.8, h_msigcom:0.075, h_snr: 8.4, k_msigcom: null, k_snr: null
FLAGS: ph_qual: BBU, rd_flg:220, bl_flg: 110, cc_flg:0c0

No optical counterpart

At the SNR peak, 275.24215 -14.33351, though no IR counterpart, there was an optical counterpart, with these properties:
b1_mag: null, r1_mag:18.83,
errors: e_ra: 10, e_dec:999, no flags.

Got the positions of the outlying sources for G16.7.
Compared the positions of the sources on the central chip with 2mass. Of the 9 sources detected on the chip, 7 had possible matches in the IR within 5 arcseconds; they all had possible matches within 9 arcseconds.

Outlined visually the positions of the chandra sources for 0931 and 1532, centered on the RASS source position, with the correct log(fx/fopt), and the offsets calculated from the RASS source.

It seems that in both cases the ROSAT source was probably not detected. The sources located closest to the expected RASS position are discussed below:

For 0931:
The RASS position is 142.829998,36.3730554
The WD position is 142.84526595, 36.36928494
RASS-WD offset: .7760754592'

The closest source to the RASS source position is located at 142.8057, 36.378942, at a distance of 1.2219', and a distance of 1.997426' from the WD. It has a u magnitude of 22.57+/-0.53, a g magnitude of 21.89+/-0.10, and thus a u-g value of .68, or with errors, between .25-1.11. It's log(f_x/f_opt)=.873428. Though it is the closest source detected, and perhaps at a plausible distance, it seems unlikely that it is in fact the ROSAT source because its chandra count rate of 5.8e-3, is much lower than the predicted chandra count rate of the RASS source, of 3.678e-2-1.559e-1.
The SDSS match to the chandra source, J093113.37+362244.0, objid: 587735240642789732, was offset from the chandra source position by 0.17028447"

For 1532,
The RASS position is 233.098415 47.446660
WD position is 233.10621952, 47.45025013
WD-RASS offset: 0.3829797676'

The closest source to the RASS position was at 233.1842, 47.401489, a distance of 4.412', and 4.3119980'away from the WD. It's u magnitude is 21.97+/-0.20, it's g magnitude was 21.03+/-0.03, and thus the u-g was .94, or somewhere in .77-1.11 when accounting for errors. The log(f_x/f_opt)=0.84207. It seems an unlikley RASS counterpart not only because of it's large distance, but also because its chandra count rate of 1.67e-2 was less than the predicted flux of the RASS source, 2.956e-2-1.092e-1.
Its optical counterpart, J153244.22+472405.2, objld: 587733442656731241, was offset from the chandra source by .17425710".

It looks to me as though, due to the difference in fluxes and pretty high positional offsets, that for both 0931 and 1532, the RASS source was not detected with chandra, even when recalculating the expected counts accounting for RASS errors in counts.


For 0931+3622 and 1532+4724

Compiled a visual of the chandra sources relative to the WD, with offset, u-g values, log(f_x/f_opt) [log(f_x/f_opt)=f_x+m_v/2.5+5.47, cts, and expected count range.

Got estimates for counts from Webpimms again, this time accounting for the uncertainty in ROSAT counts. Results were as follows:

0931: n_H=1.42E+20 (.009-.025cps)
0.9e-2cps:
.06KeV: I-2.106e-3
S-3.678e-2
.1KeV: I-1.151e-2
S-5.611e-2

2.5e-2cps:
.06KeV: I-5.850e-3
S-1.022e-1
.1KeV: I-3.198e-2
S-1.559e-1

So counts should be in a range for the I array of (2.106e-3 - 3.198e-2) and for S array of (3.678e-2 - 1.559e-1)

1532: n_H=1.7 (.007-.017cps)

0.7e-2:
.06KeV: I-1.831e-3
S-2.956e-3
.1KeV: I-9.543e-3
S-4.496e-2
1.7e-2cps:
.06KeV: I-4.447e-3
S-7.179e-2
.1KeV: I-2.318e-3
S-1.092e-1

So for the I array the cps should be within (1.831e-3 - 2.318e-3) and for the S array within (2.956e-3 - 1.092e-1)

275.23312 -14.32476.



With USNO B1.0 with gator;
Distance: 2.052775"
RA: 275.233659, DEC:-14.324989, e_ra: 82, e_dec:69, b1_mag: 15.48, r1_mag: 13.54, no flags.

With USNO B1.0 with "Integrated Image and Catalog Archive Service"



With USNO A2.0:



Visual from DSS survey:


With 2Mass with Gator:
One source was found within 5" of the chandra source, at a distance of 2.039001:
RA: 275.233684, DEC: -14.324909, err_maj: 0.06, err_min: 0.06, err-ang: 90, j_mag:12.093, j_msigcom:0.023, j_snr:323.8, h_m: 11.612, h_msigcom:0.028, h_snr: 94.2, k_mag: 11.402, k_msigcom: 0.030, k_snr: 91.3, FLAGS: ph_qual: AAA, rd_flg:222, bl_flg: 111, cc_flg:000, j-h=0.4810, h-k=0.2100, j-k=0.6910

I think there is defiantly evidence of a matching source in the optical and infrared here, so not the pulsar...