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Chandra Electronic Announcement #94

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1. Chandra Cycle 16 Call for Proposals released 12 December 2013
2. CIAO 4.6 released 12 December 2013

Item 1:  Chandra Cycle 16 Call for Proposals released 12 December 2013

The CXC is pleased to announce the release of the Chandra Cycle 16
Call for Proposals (CfP). The Call for Proposals, the Proposers'
Observatory Guide (POG), proposal planning software, and general
information are posted on the "Proposer" web page at the CXC website:

Proposals are due: 13 March 2014

Hardcopy documents are available on request to the CXC HelpDesk

What's New in Cycle 16

*The XVP Program:

 Given the reduction in observing time available in this and future
 cycles due to the expected evolution of Chandra's orbit, the 5.5 Ms of
 time to be allocated to XVP programs this cycle will be drawn from
 Cycles 16 and 17. There will be no XVP call included in Cycle 17. The
 next XVP call will depend on a review of the available observing time
 in advance of Cycle 18. See Section 4.3 of the CfP for details.

*New Joint Program:

 The NuSTAR X-Ray Observatory ( is
 making available up to 500 ksec of NuSTAR observing time to joint
 science proposals. Refer to Section 4.5 of the CfP for details.

*Science Keywords:

 The RPS proposal Cover Page now requires at least three keywords
 describing proposal science. Selected keywords may be used to
 facilitate preliminary matching of proposals to reviewers, as well as
 archive searches. See Section 5.2.2 of the CfP.

*ACIS Optional CCDs

 The CXC now encourages observers to specify a total of 4 or fewer ACIS
 CCDs as required (i.e., "Y" in the RPS form). Additional optional CCDs
 may be selected (as "Off#" in the RPS form, where e.g., "Off1"
 specifies which CCD should be turned off first if the satellite
 thermal state is unfavorable).  Up to five CCDs may be specified as
 "required". Those requesting 6 CCDs must specify at least one optional
 CCD at the time of proposal submission. Details can be found at or
 Section 6.20.1 of the POG.

*Proposal Search:

 A new tool to search for PI, title and abstract of approved
 (observing, archive, and theory) proposals is now available at

Item 2: CIAO 4.6 released 12 December 2013

CIAO 4.6 released 12 December 2013

The Chandra X-ray Center (CXC) is pleased to announce that version 4.6
of CIAO ("Chandra Interactive Analysis of Observations") is  available
for download from:

Notable changes and improvements in CIAO 4.6:

Two new tools have been added to help automate the detection of the
0th order location in grating observations: tg_choose_method and

Sherpa template models have been enhanced to include interpolation
between the individual table models. Users can now use templates with
all the fit methods (previously only gridsearch was valid).

The new srcflux script automates the steps necessary to calculate the
net counts, rates, and fluxes, with confidence intervals, for Chandra
sources given source and background regions. The script can estimate
upper limits as well as detections and can account for the PSF
contribution to both the source and background regions, for point
sources. Be sure to check the caveats section for cases not handled
well by the script (eg cc mode, pileup, crowded fields etc).

The ACIS parameter-block filename parameter, pbkfile, in mkarf,
mkgarf, mkwarf, eff2evt, and mean_energy_map is no longer used. The
information is now encoded in the archived data products created with
ASCDSVER 8.4.2 and later or reprocessed with chandra_repro. Users with
older data who choose not to reprocess their data, can use the new
r4_header_update script.

The suite of hotpixel tools: acis_run_hotpix, acis_find_hotpix, and
acis_classify_hotpix has been withdrawn from CIAO. The
acis_detect_afterglow tool is now the best tool available to identify
cosmic ray afterglows without losing a large fraction of events from
bright sources.

A problem affecting the area calculation when complex regions are
selected, has been corrected. This problem affected regions which
include multiple overlapping shapes. Simple regions were not affected
(for more details see the Region section under Libraries).

Read the complete CIAO 4.6 release notes at


CIAO 4.6 is distributed for the following platforms:

* Linux 32-bit and 64-bit
* Mac OS X Intel 10.6 (Snow Leopard), 10.7 (Lion),
10.8 (Mountain Lion), 10.9 (Mavericks) 64-bit

More details at


There is no new Calibration Database (CALDB) associated with this CIAO
release. The latest CALDB version 4.5.9 was released on 19 November 2013.

Detailed information can be found in the Chandra
Calibration Database website at


As always please send questions and requests for enhancements to the CXC
HelpDesk (

CIAO 4.6 is a collaborative effort between the SAO/CXC Science Data
Systems, the SAO/CXC Data Systems, and MIT/CXC personnel.

Antonella Fruscione (for the CIAO development team)

Last modified: 12/12/13

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