Transcript ausac_cjs_2008_1

Radio Astronomy -- Other Than
ALFA Surveys
Chris Salter (NAIC/Arecibo
Observatory)
AUSAC Meeting · March 17-18, 2008
The Rules of the Game
• Pre-Nov 2006:
-- 50% of R.A. telescope time for non ALFAsurvey astronomy (~2400 hr per yr).
-- Rx available: 327, 430 & 610 MHz; LBW,
SBW, SBH, CB, CBH & XB.
• Post-Nov 2006:
-- 20% of R.A. telescope time for non ALFAsurvey astronomy (~750 hr per yr).
-- Rx available: 327 & 430 MHz; LBW, CB &
XB; (SBW, SBH & CBH on “campaign”
basis).
AUSAC Meeting · March 17-18, 2008
Pulsar Study: The “Planets Pulsar”
Alex Wolszczan is completing a 17-yr
study of the “planets pulsar”, PSR
B1257+12. His timing fits includes;
• All PSR parameters
• Astrometric parameters
• Three planets (including the mutual
perturbations of Planets b & c)
430-MHz Raw Residuals
1400-MHz Raw Residuals
•DM variations (3rd panel).
Highlights of 17-yr Study of B1257+12
• First exoplanets.
• First detection of planets in mean
Residuals including DM Variations
motion resonance (MMR 3:2).
• First multiplanet system.
• First terrestrial-mass system.
• First dynamical analog of the inner solar
Dispersion Measure (DM) Variations
system (scaled down by a factor of ~2).
AUSAC Meeting · March 17-18, 2008
Continuum Studies
Combining DRAO Interferometer and
Arecibo 400-MHz data, Kronberg et al.
have imaged an 8º  8º region in the P-P
supercluster to examine the nature of the
low-level emission. The Arecibo images
were CLEANed before being combined
with those from DRAO. The angular
resolution of the image is 10 arcmin.
Minchin et al observed galaxies from the
Scuba Local Universe Galaxy Survey
(SLUGS) at 3, 5, 7 & 9 GHz to characterize
their synchrotron emission to find its
contribution to their 850 µm fluxes. This
allowed corrected estimates of their cold dust
masses.
AUSAC Meeting · March 17-18, 2008
HI emission from Disk Galaxies at z~0.2
B. Catinella (MPA, Arecibo), M. Haynes, R. Giovanelli (Cornell), J. Gardner, A. Connolly (UPitt)
 Sample selected from SDSS according to redshift (0.16<z<0.27), optical
(Hα) emission line strength, inclination (>45o), disk morphology, and
relative isolation.
 Observations in standard position-switching mode, L-band wide.
 41 galaxies targeted.
 26 detections + 8 tentative ones
 HI mass 3 − 8 × 1010 M‫סּ‬
 ON-source integration time between 1 and 4 hr per object
 280 hr telescope time including overheads.
SDSS
ARECIBO
z=0.195
SDSS
0.203
0.219
Catinella et al. in preparation
ARECIBO
z=0.224
0.245
0.262
Gas fraction vs stellar mass
Evolution effects?
z ~ 0.2
Need a fair sample
of massive (HI, M*),
z~0 galaxies for
comparison!!
z~0
Virgo cluster
Black: Virgo cluster (GOLDMINE +
ALFALFA, Gavazzi et al. 2008)
Catinella et al. in preparation
HI from Black-hole Host Galaxies
Ho, Darling and Greene have made a large
survey of 154 nearby Type-1 (broad-lined) AGNs
whose black-hole masses and accretion rates are
known. This enables them to constrain a number
of properties of relevance to the relationship
between BHs and their hosts. HI was detected in
a high percentage of the targets.
HI spectra yield:
• Maximum rotation velocity of disk.
• Estimate of galaxy luminosity via Tully-Fisher.
• Using the optical disk size, an estimate of the
dynamical mass of the galaxy.
• A first-order estimate for the cold-gas content
of the galaxy.
Ho, Darling & Greene
AUSAC Meeting · March 17-18, 2008
HI from Black-hole Host Galaxies II
B-band Tully-Fisher relation for
sample. Apart from larger scatter,
No gross differences between active
And inactive galaxies.
Black-hole mass vs Dynamical mass
of host galaxy
Distribution of MHI/LB for the
host galaxies and a large sample
of inactive galaxies. Similar distribution
for later types, but early type active
galaxies appear more gas-rich.
Ho, Darling & Greene
AUSAC Meeting · March 17-18, 2008
Molecular Line Studies: IRAS 18566+0408
• No. of Galactic H2CO masers = 7
• A recent Arecibo H2CO survey of low-mass star
forming regions
showed these masers are exclusively
`
associated with high-mass star formation.
The H2CO maser in IRAS 18566+0408 was
discovered at Arecibo in 2002.
 Three short-term H CO flares (∆t<3 months) have
2
been observed to date via systematic Arecibo
monitoring.
 The flare amplitudes appear to be linearly decreasing.
 The outbursts appear periodic (P ~ 8 months)
 The next flare is predicted to occur in Apr 08, and will
be looked for.
The H CO flares are time-correlated with 6.67-GHz
2
CH3OH flares. Most of the CH3OH frequency
components show flares that are delayed by a month,
but one is prompt.
 High resolution follow-up with the EVLA and MERLIN
is planned to investigate the phenomenon in detail.

Araya, Hofner, Linz, Kurtz & Creech-Eakman
AUSAC Meeting · March 17-18, 2008
Pre-biotic Molecules and Other Lines in ULIRGs
(a) Arp 220
(b) Other ULIRGs
IC 860
Emission from the 110–111 methanimine (CH2NH)
multiplet, (the 6 transitions shown by vertical lines.)
This is likely to represent weak maser emission.
Line detections in IC 860: (Top) HCN v2=1, J=4 and
excited-OH (4660 MHz) absorption lines:
(Bottom) H2CO and CH2NH emission lines,
v2=1 direct l-type absorption lines of HCN (J = 4, 5 and
6. An excitation temperature of ~120-150 K is implied.
Non-detection of the J=2 level is likely to be due is to
free-free absorption in the foreground ionized ISM.
H109α recombination line in NGC 3628
Latest News: Detection of v2=1, J=3, HCN in Arp 220 (2645 MHz) gives a line-center optical depth,  ~ 3 at 1630 MHz.
(ULIRG = Ultra-Luminous Infra-Red Galaxy)
AUSAC Meeting · March 17-18, 2008
Future Option: Single-Pixel “pdev/edev”
The anticipated “single-pixel” mode of operation for the new “pdev/edev” spectrometers
offers exciting possibilities for, e.g. broad-band (bandwidths up to 2 GHz) pulsar
observing, and line searches in Galactic and extragalactic targets. Reasonable
parameters for a Galactic spectral scan, (velocity resolution ~ 0.5 kms-1), could be:
Note: All but X-band would use an instantaneous bandwidth of 1 GHz, which is
presently available.
AUSAC Meeting · March 17-18, 2008