Friday, March 13, 2015

SALT Status Updates for March 2015

Janusz Kaluzny
--------------

We are saddened by the untimely passing of Janusz Kaluzny on 6 March
2015.  Janusz, of the Nicolaus Copernicus Astronomical Center in
Poland, was involved in SALT from its very first days, and throughout
the project devoted his time and wisdom to ensuring that SALT would
live up to the high expectations of it.  His contributions, both
scientific and technical, will be missed.


SALT Operations
--------------- 

After running the Astronomy Operations for 10 years, David Buckley has
taken a sabbatical and will return to SAAO and SALT related projects
as SALT Scientist at the end of this year.

Chris Coetzee has been named the SALT Operations Manager and any
issues or feedback regarding management of the operations and process
as a whole should be addressed to him at chris_at_salt.ac.za.  Petri
Vaisanen has taken over as the Head of SALT Astronomy Operations since
mid-January.  Any questions relating to SALT science and programs
should be addressed to him at petri_at_saao.ac.za or
saltastrohead_at_saao.ac.za.  Normal operations and on-going programs
continue to be handled by the assigned individual Liaison SAs as
previously.

DDT proposals and questions should be sent to ddt_at_saao.ac.za. DDT
proposals are assessed by the SAAO director Ted Williams and Petri
Vaisanen. More details at
http://astronomers.salt.ac.za/proposals/directors-discretionary-time/



SALT Papers since November
--------------------------

In 2014, 33 papers were published that included SALT data.  Already,
2015 is off to a great start and here are some of the refereed papers
that have been published this year (and please do let us know of SALT
papers we may have omitted):

* Mitchell et al. published the first results from RINGS -- a
Fabry-Perot survey of a nearby galaxies.
http://adsabs.harvard.edu/abs/2015AJ....149..116M

* Kalari and Vink present optical spectra of pre-main-sequence
candidates in the Low Metallicity Galactic Star-forming Region Sh
2-284 http://adsabs.harvard.edu/abs/2015ApJ...800..113K

* Milisavljevic report on the  Broad-lined Type Ic SN 2012ap and its lack of gamma ray detection.
http://adsabs.harvard.edu/abs/2015ApJ...799...51M

* Mamajek et al. present the closest known flyby of a star, WISE
J0720, to the Solar System (see below for PR).
http://adsabs.harvard.edu/abs/2015ApJ...800L..17M

* Ivanov et al. present characteristics of the solar neighbour WISE
J0720 (see below for Press Release).
http://adsabs.harvard.edu/abs/2015A%26A...574A..64I

* Stritzinger et al. include RSS spectra in their comprehensive study
of the bright and energetic Type Iax SN 2012Z.
http://adsabs.harvard.edu/abs/2015A%26A...573A...2S

* Kniazev, Gvaramadze, and Berdnikov discover a new galactic luminous
blue variable star (see below for Press Release)
http://adsabs.harvard.edu/abs/2015MNRAS.449L..60K


* Manick, Miszalski, and McBride publish first results of a radial
velocity survey of post-common-envelope Wolf-Rayet central stars of
planetary nebulae.  http://adsabs.harvard.edu/abs/2015MNRAS.448.1789M


For a full listing of all the papers published in 2014, please see:
http://astronomers.salt.ac.za/data/publications/


SALT Science Conference 2015
----------------------------

Registration for 'Science with SALT' conference to be held at the
Stellenbosch Institute of Advanced Study (STIAS) from 1-5 June is now
open.  Please visit the conference website for more information:
http://ssc2015.salt.ac.za/


SALT in the News
----------------

Recently SAAO issued two SALT related Press Releases.  One about the
closest known stellar fly-by of a late type star / brown dwarf binary
intruder through the Oort Cloud 70.000 years ago and the other about
finding a rare Luminous Blue Variable star.

http://www.saao.ac.za/press-release/a-neighbourhood-stars-close-shave-with-our-solar-system/

http://www.saao.ac.za/press-release/discovery-of-a-new-luminous-blue-variable-star/


Long-time scale studies of High Redshift Quasars
------------------------------------------------

Justyna Modzelewska from CAMK along with her collaborators have been
using SALT to monitor the variability of high redshift quasars with
the goal of eventually using these objects to help study Dark Energy.
They have published some of their early results and you can read all
the details in the blog post here:
http://saltastro.blogspot.com/2014/10/salt-long-slit-spectroscopy-of-cts.html


SALT DDT followup of MASTER transients
---------------------------------

As part of a SALT Directors Discretionary Time program, snapshot RSS
spectroscopic observations were undertaken of three MASTER SAAO
transients in order to optically identify them. They were subsequently
identified (and the results published in Astronomers Telegrams) to be
a Dwarf Nova declining from outburst (Atel #7165), a flaring FSRQ
blazer, at a redshift of 0.90 (Atel #7167), and an eclipsing Polar
with a 2.1 h orbital period (Atel #7169). The latter was determined
from follow-up photometry on the SAAO 1.9-m and 1.0-m telescopes using
the high speed SHOC cameras. This was conducted during a campaign of
CV photometry undertaken by UCT graduate students Hannes Breytenbach
and Mokhine Motsoaledi, together with John Thorstensen and students
from Dartmouth College, who have been visiting SAAO and UCT for the
summer.


Phase-1 proposals for 2015-1
----------------------------

We received 76 proposals for the upcoming Semester 2015-1 starting May
1.  The process is now with the various Time Allocation committees.
For all proposals, the time available was oversubscribed by a factor
of 1.3. The successful PIs will be informed by the Ast Ops by 1 April
and phase-2 material will be expected to be submitted by 17 April.


RSS throughput
--------------

We are very happy to announce a significant improvement of the RSS
optics throughput after the RSS optics fix in September/October. The
efficiency increase is approximately a factor of 1.4 and even better
in the blue.  More details are available here:
http://saltastro.blogspot.com/2015/03/news-on-rss-throughput.html


RSS Fabry-Perot mode 
-------------------- 

After the re-installation of RSS in November we have unfortunately
struggled to get the FP mode stable and calibrated.  New cabling was
required which arrived only in January.  Calibrating all the required
wavelength regions has been slow due to various technical issues, but
we are making progress are are confident that both LR and MR are back
on-sky during this month. The good news is that LR mode is on-line
after a long period off-line in 2013-2014.

We do sincerely apologize for significant loss of valuable time for
accepted FP programs during 2014-2.

News on RSS Throughput

A major cleaning of RSS optics took place in September/October 2014 during which optical
coupling fluids in the collimator were replaced as well. Early pre-installation laser measurements
and relative standard star measurements post-installation indicated approximately 30 to 40%
increase in RSS throughput. In January 2015 we were able to verify absolute RSS throughput
values on-sky using so called burst-mode observations: the primary mirror is purposefully misaligned
to have each 1-metre segment produce an individual image of a standard star. An example on the
right shows the imaging field of RSS: the pattern of points left of the centre is actually the spectrophotometric standard EG 21. Photometry is performed on each individual point and since the size of each mirror is now constant, absolute efficiencies of the system can be derived (assuming many other variables such as extinction, primary mirror efficiency, filter transmissions, etc. are known). 



These results confirm the significant throughput improvement. RSS efficiency
increase by a likely 50%, and possibly even more in the bluest wavelengths. The Figure
on the left shows the overall Telescope+RSS throughput development since 2011 until now.
There had been a steady decrease since 2011, with the red points showing the pre-fix
September 2014 values. The green points show the current situation.



Telescope throughput has been measured as well (with some caveats) and assuming it was
constant from September 2014 until now the figure on the left shows the RSS Optics only
efficiency. While the very reddest wavelength points may be artificially a little “too” high,
the overall trend is very encouraging.


Night Log 2015-03-12

SA: Luke
SO: Veronica
Others:

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Summary
----------------------------------------------------------------------


A fairly productive night with reasonable seeing and 1x P0, 2x P1 and 2x P3 targets observed. Closed prematurely due to high humidity, causing us to miss 2x P0 and 1x P1 blocks.

2014-2-SCI-034 P0 RSS (Classification of possible supernovae)
2014-2-SCI-057 P1 RSS (Exploring magnetic accretion in Intermediate Polars)
2014-2-SCI-054 P1 RSS (Measuring radial velocitie sin the spectrum of CAL 87)
2014-2-SCI-060 P3 RSS (Searching for binaries in unusual central stars of planetary nebulae)
2014-2-SCI-017 P3 RSS (Optical preparatory survey for Cold HI 21-cm Absorption Line Survey (CHITALS))

Thursday, March 12, 2015

Night Log 2015-03-11

SA: Luke
SO: Veronica
Others: Keith and Janus remotely

----------------------------------------------------------------------
Summary
----------------------------------------------------------------------


Opened late due to rain and closed early due to high humidity. In the meantime performed SAMS mirror alignment tests, 1x P2 time-critical observation with slotmode SALTICAM and 3x P3 observations with RSS longslit spectroscopy. Also a full compliment of RSS and HRS lamp calibrations.

Data taken for:

2014-1-MLT-003 P2 SCAM (Observe the accretion disc as a white dwarf, neutron star or black hole gobbles up a companion.)
2014-2-SCI-060 P3 RSS (x3) (Searching for binaries in unusual central stars of planetary nebulae)

Wednesday, March 11, 2015

Night Log 2015-03-10

SA: Encarni
SO: Veronica
Others: Sunil Chandra, Thembela, Luke. Etienne and Jonathan to help with the payload.

----------------------------------------------------------------------
Summary
----------------------------------------------------------------------


Mostly clear night with poor seeing, rising humidity and technical problems. Had to close at 2:30 am.

Science data for:

2014-2-SCI-060 P3 RSS (Searching for binaries in unusual central stars of planetary nebulae)

Tuesday, March 10, 2015

Night Log 2015-03-09

SA: Encarni
SO: Veronica
Others:

----------------------------------------------------------------------
Summary
----------------------------------------------------------------------


A partly cloudy night with very nice seeing through the clouds. Thicker patches of cloud and, at the end of the night, a technical problem prevented us from taking full advantage of the good seeing.

Science data for:
2014-2-SCI-074 P2 SCAM (Observations of Dwarf Novae in the Large Magellanic Cloud)
2014-2-SCI-060 P3 RSS (x2) (Searching for binaries in unusual central stars of planetary nebulae)
2014-2-SCI-055 P3 RSS (x3) (Multi-wavelength classification of unidentified Blazar-like Fermi 2LAC catalogue sources)
2014-1-MLT-001 P3 RSS (Observations of supernovae, near and far.)

Monday, March 9, 2015

Night Log 2015-03-08

SA: Encarni
SO: Veronica
Others: Thabelo observing with us until ~midnight.

----------------------------------------------------------------------
Summary
----------------------------------------------------------------------


Another clear night! This one with variable seeing. Had to close for a while due to rising humidity, which later dropped like a lead balloon and allowed us to open again to continue observing.

Nine science blocks for:
2014-1-MLT-001 P0 RSS (Observations of supernovae, near and far.)
2014-2-SCI-016 P2 HRS (x2) (Investigating the birth and evolution of X-ray binaries through their radial motion.)
2014-2-SCI-060 P3 RSS (x3) (Searching for binaries in unusual central stars of planetary nebulae)
2014-2-SCI-045 P3 HRS (x2) (Chemical composition determination of LBVs in the Southern Hemisphere.)
2014-2-SCI-047 P3 RSS (Study of the properties of thin and thick disks of galaxy IC2531)