sukye

ghost file

FATAL ERROR: Output Reference WCS “72_wcs.fits” already exists! Please delete.
–> delete 72_wcs.fits
Warning: Attempt to delete a nonexistent file (72_wcs.fits)

———
http://server.ccw.com.cn/yyjq/htm2005/20050906_0994b.htm
find . -name “graphcap” -print

how to use tweakshifts

we could register images precise to 0.1 pixel by iterating multidrizzle (mul) and tweakshifts (twe). since twe only works when the shifts are within 1 pixel or there are tiny rotations, we have to find the rough shifts by hand.

step 0.
create files list to be the input:
list_mul:
—————-
a_flt.fits
b_flt.fits
—————-
list_twe:
—————-
a_single_sci.fits
b_single_sci.fits
—————-
The first file will be the reference image.

step 1.
create the refimage:
mul a_flt.fits
imcopy a_single_sci.fits refimage.fits

step 2.
mul @list_mul
*turn off all the steps of mul except driz_separate+
*keep temporary files: clean=no
*no difference for updatewcs=yes or no

step 3.
measure the relative shifts manually from the *single_sci.fits
*choose 2-5 stars far away in the images and use e.g. imexam to find their positions.
*create the shiftfile:
—————-
# frame: output
# reference: refimage.fits
# form: delta
# units: pixels
a_flt.fits 0.0 0.0
b_flt.fits -3.4 -5.1
—————-

step 4.
repeat step 2. and
*refimage=refimage.fits
*shiftfile=shiftfile

step .5
repeat step 3. and if the additional shifts are within 1 pixel continue with step 7. otherwise, step 6.

step 6.
if the shifts in x axis (or y axis) for the stars are of the same sign, goto step 4. otherwise, rotational adjustment is needed.
—————-
# frame: output
# reference: refimage.fits
# form: delta
# units: pixels
a_flt.fits 0.0 0.0 0.0 1.0
b_flt.fits -3.4 -5.1 359.9 1.0
—————-
goto step 4.

step 7.
twe @list_twe
*undisturb=no
*no difference if shiftfile is provided
*fitgeometry=shift
*clean=no
check the output shiftfile: all shifts should be <１pixel, and add them to shiftfile for mul.
find out the best parameters of twe to ensure 10-60 objects matched (but 3 or 150 may be also acceptable).
*fwhmpsf=3.0-2.0
*tolerance=3.0-0.5
*threshold=10.0-2.0
#optional: use e.g. tvmark to check those matched objects. it cant be done if the images
are opened by ds9. so,
>display b_single_sci.fits 1 zr- zs- z1=0.01 z2=6 ztrans=log
>tvm b_single_sci.match

step 8.
repeat step 4. and then step 7.
the numbers of matched objects should be no less than those of the last run and the shifts produced by twe should also be decreasing .

step 9.
repeat step 7. when all the shifts suggested by twe are < 0.1 pixels.
*it’s possible it’s only reachable for 0.2 pixels

Thanks to Max Mutchler and Warren J. Hack. They are really experts.
http://www.stsci.edu/hst/acs/documents/handbooks/DataHandbookv2/acs_Ch47.html
http://www.stsci.edu/hst/wfpc2/analysis/WFPC2_drizzle_registration.html
http://forums.stsci.edu/phpbb/viewtopic.php?p=172

astro-ph 0802w1

The Subaru/XMM-Newton Deep Survey (SXDS)
http://arxiv.org/abs/0801.4017
B=28.4, V=27.8, Rc=27.7, i’=27.7 and z’=26.6, 1.22 deg^2

Measuring the Fraction of Obscured Quasars by the Infrared Luminosity of Unobscured Quasars
http://arxiv.org/abs/0801.3849
collected archival 24 micron MIPS photometry from objects with z~1 in SDSS, GOODS, and COSMOS.
Although we find approximate agreement, our method indicates somewhat higher values of f_obsc, particularly in the middle range of luminosities, suggesting that there may be a significant number of heavily obscured AGN missed by X-ray surveys.

tbc

astro-ph 0801w4

NICMOS Measurements of the Near Infrared Background
http://arxiv.org/abs/0801.3825
he near infrared background is now spatially resolved and is dominated by galaxies in the redshift range between 0.5 and 1.5

Estimating the Redshift Distribution of Faint Galaxy Samples
http://arxiv.org/abs/0801.3822
assigns weights to galaxies in a spectroscopic subsample such that the weighted distributions of photometric observables (e.g., multi-band magnitudes) match the corresponding distributions for the photometric sample. The weights are estimated using a nearest-neighbor technique that ensures stability in sparsely populated regions of color-magnitude space. The derived weights are then summed in redshift bins to create the redshift distribution.

Optical monitoring of the z=4.40 quasar Q 2203+292
http://arxiv.org/abs/0801.3729

Confirmation of a correlation between the X-ray luminosity and spectral slope of AGNs in the Chandra Deep Fields
http://arxiv.org/abs/0801.3599
0.1 < z < 4

Large Scale Structures at High Redshift in the GOODS Field
http://arxiv.org/abs/0801.3557
GOODS-South, catalogue of overdensities, up to z ~ 2.5

*Detecting quasars at very high redshift with next generation X-ray telescopes*
http://arxiv.org/abs/0801.3482
modelling of the evolution of the optical and X-ray AGN luminosity function at 2 < z < 6 based on a CDM merger-driven model

Difference Imaging of Lensed Quasar Candidates in the SDSS Supernova Survey Region
http://arxiv.org/abs/0801.3432
Difference imaging provides a new way to discover gravitationally lensed quasars because few non-lensed sources will show spatially extended, time variable flux.

Can very massive stars avoid Pair-Instability Supernovae?
http://arxiv.org/abs/0801.3397
magnetic fields provide the strong coupling that is lacking in standard evolution metal-free models and our 150 Msol Population III model avoids indeed the pair-instability explosion.

Astroparticle Physics: Puzzles and Discoveries
http://arxiv.org/abs/0801.3028

astro-ph 0801w3

http://arxiv.org/abs/0801.2759
Spitzer Uncovers AGN Missed by Optical Surveys in 7 Late-type Galaxies
Our findings add to the growing evidence that black holes do form and grow in low-bulge environments and that they are significantly more common than optical studies indicate.

http://arxiv.org/abs/0801.2694
Milli-arcsecond astrophysics with VSI, the VLTI spectro-imager in the ELT era
This instrument will provide information complementary to what is obtained at the same time with ALMA at different wavelengths and the extreme large telescopes.

http://arxiv.org/abs/0801.2484
Quantifying systematic uncertainties in supernova cosmology
While the tool is primarily aimed for studies and optimization of future instruments, we use the “Gold'’ data-set in Riess et al. (2007) to show examples of potential systematic uncertainties that could exceed the quoted statistical uncertainties.

http://arxiv.org/abs/0801.2383
Observational Constraints on the Dependence of Radio-Quiet Quasar X-ray Emission on Black Hole Mass and Accretion Rate
alpha_ox increases with increasing M_BH and L_UV / L_Edd, and decreases with increasing L_X / L_Edd.

http://arxiv.org/abs/0801.2141
Mapping warm molecular hydrogen with Spitzer’s Infrared Array Camera (IRAC)
David Neufeld, Yuan Yuan (JHU)