J/ApJ/812/81 Arecibo Pulsar-ALFA (PALFA) survey. IV. (Lazarus+, 2015)
Arecibo Pulsar survey using ALFA.
IV. Mock spectrometer data analysis, survey sensitivity, and the discovery
of 40 pulsars.
Lazarus P., Brazier A., Hessels J.W.T., Karako-Argaman C., Kaspi V.M.,
Lynch R., Madsen E., Patel C., Ransom S.M., Scholz P., Swiggum J.,
Zhu W.W., Allen B., Bogdanov S., Camilo F., Cardoso F., Chatterjee S.,
Cordes J.M., Crawford F., Deneva J.S., Ferdman R., Freire P.C.C.,
Jenet F.A., Knispel B., Lee K.J., van Leeuwen J., Lorimer D.R., Lyne A.G.,
McLaughlin M.A., Siemens X., Spitler L.G., Stairs I.H., Stovall K.,
Venkataraman A.
<Astrophys. J., 812, 81 (2015)>
=2015ApJ...812...81L 2015ApJ...812...81L (SIMBAD/NED BibCode)
ADC_Keywords: Pulsars ; Surveys ; Radio continuum
Keywords: methods: data analysis; pulsars: general
Abstract:
The on-going Arecibo Pulsar-ALFA (PALFA) survey began in 2004 and is
searching for radio pulsars in the Galactic plane at 1.4GHz. Here we
present a comprehensive description of one of its main data reduction
pipelines that is based on the PRESTO software and includes new
interference-excision algorithms and candidate selection heuristics.
This pipeline has been used to discover 40 pulsars, bringing the
survey's discovery total to 144 pulsars. Of the new discoveries, eight
are millisecond pulsars (MSPs; P<10ms) and one is a Fast Radio Burst
(FRB). This pipeline has also re-detected 188 previously known
pulsars, 60 of them previously discovered by the other PALFA
pipelines. We present a novel method for determining the survey
sensitivity that accurately takes into account the effects of
interference and red noise: we inject synthetic pulsar signals with
various parameters into real survey observations and then attempt to
recover them with our pipeline. We find that the PALFA survey achieves
the sensitivity to MSPs predicted by theoretical models but suffers a
degradation for P≳100ms that gradually becomes up to ∼10 times worse
for P>4s at DM<150pc/cm3. We estimate 33±3% of the slower pulsars
are missed, largely due to red noise. A population synthesis analysis
using the sensitivity limits we measured suggests the PALFA survey
should have found 224±16 un-recycled pulsars in the data set
analyzed, in agreement with the 241 actually detected. The reduced
sensitivity could have implications on estimates of the number of
long-period pulsars in the Galaxy.
Description:
The Arecibo Pulsar-ALFA (PALFA) survey observations have been
restricted to the two regions of the Galactic plane (|b|<5°)
visible from the Arecibo observatory, the inner Galaxy
(32°≲l≲77°), and the outer Galaxy (168°≲l≲214°).
Integration times are 268s and 180s for inner and outer Galaxy
observations, respectively.
Observations conducted with the 7-beam Arecibo L-band Feed Array
(ALFA) receiver of the Arecibo Observatory William E. Gordon 305m
Telescope have a bandwidth of 322MHz centered at 1375MHz. PALFA survey
data have been recorded with the Mock spectrometers since 2009.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table5.dat 46 40 *Pulsars discovered in mock spectrometer data
with the PRESTO pipeline
table6.dat 50 128 Known pulsars re-detected in mock spectrometer
data with the PRESTO pipeline
--------------------------------------------------------------------------------
Note on table5.dat: The discovery positions of the pulsars reported in this
paper are only good to ∼3 arcmin. The PALFA collaboration is conducting
follow-up observations that will (among other things) result in precise
positions.
--------------------------------------------------------------------------------
See also:
VII/189 : Catalog of Pulsars (Taylor+ 1995)
J/ApJS/218/11 : The 5yr Fermi/GBM magnetar burst catalog (Collazzi+, 2015)
J/ApJ/804/23 : 327MHz observations of 124 pulsars (Krishnakumar+, 2015)
J/ApJS/212/6 : The McGill magnetar catalog (Olausen+, 2014)
J/ApJS/208/17 : 2nd Fermi LAT cat. of gamma-ray pulsars (2PC) (Abdo+, 2013)
J/ApJ/769/108 : Optical photometry of 4 millisecond pulsars (Breton+, 2013)
J/MNRAS/424/2832 : Pulsars in γ-ray sources (Lee+, 2012)
J/AJ/139/2130 : ALFA-ZOA precursor observation (Henning+, 2010)
J/AZh/84/685 : Scattering of pulsar radio emission (Kuz'min+, 2007)
J/MNRAS/372/777 : Parkes Multibeam Pulsar Survey. VI. (Lorimer+, 2006)
J/AZh/83/542 : Integrated Radio Luminosities of Pulsars (Malov+, 2006)
J/MNRAS/359/1524 : 10 new pulsars in Arecibo drift-scan survey (Lorimer+, 2005)
J/ApJ/605/759 : Multifrequency obs. of radio pulse broadening (Bhat+, 2004)
J/AZh/79/501 : Radio luminosities of normal + ms pulsars (Kuz'min, 2002)
J/MNRAS/328/17 : Parkes Multi-Beam Pulsar Survey (Manchester+, 2001)
J/AZh/77/499 : Flux densities of 235 pulsars at 102.5MHz (Malofeev+, 2000)
J/A+AS/147/195 : Pulsar spectra of radio emission (Maron+, 2000)
J/A+AS/136/571 : Pulsars identified from the NRAO VLA Sky Survey (Han+ 1999)
J/ApJS/121/171 : Arecibo polarimetry of 98 pulsars (Weisberg+, 1999)
J/AZh/71/762 : Radio luminosities of 232 pulsars (Malov+, 1994)
http://www.atnf.csiro.au/research/pulsar/psrcat/ : The ATNF pulsar database
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- PSR Pulsar name (JHHMM+DDMM or JHHMM+DD)
12 A1 --- f_PSR [be] Flag on PSR (1)
14- 20 F7.2 ms Per [2.5/1779.3] Period (P)
22- 27 F6.1 pc/cm3 DM [32.9/1103.6] Dispersion measure (DM)
29- 33 F5.2 --- Sig [6.5/26.7] Significance (σF)
35- 39 F5.3 mJy Flux [0.02/0.4]? Phase average 1.4GHz flux density (2)
41- 44 F4.2 mJy e_Flux [0.04/0.09]? 1σ error on Flux
46 A1 --- f_Flux [cd] Flag on Flux (1)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
b = Pulsar was previously published by Scholz et al. (2015ApJ...800..123S 2015ApJ...800..123S).
c = Flux calibrated using noise diode.
Value from Scholz et al. (2015ApJ...800..123S 2015ApJ...800..123S).
d = Refined position not available. Flux density could not be estimated.
e = Pulsar was first identified using the PICS machine learning candidate
selection system described in Section 3.5.2.
Note (2): Phase-averaged flux density determined using the radiometer equation
(see Section 4.1) unless otherwise noted.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- PSR Pulsar name (BHHMM+DD or JHHMM+DDMM or
JHHMM+DD)
12- 18 F7.2 ms Per [1.5/2712.5] Period (1)
20- 25 F6.1 pc/cm3 DM [11.1/1042.6] Dispersion measure (1)
27- 31 F5.2 mJy S1400a [0.1/42]? ATNF S1400 (1.4GHz) flux (1)
33- 36 F4.2 mJy e_S1400a [0.01/6]? S1400a uncertainty (1)
38- 43 F6.1 --- S/N [5.3/1453.2] Measured signal to noise ratio
45- 50 F6.3 --- S1400 [0.08/24.5]? Measured 1.4GHz flux density
(S1400)
--------------------------------------------------------------------------------
Note (1): Values for period, DM, and "ATNF S1400" are taken from the
Australia Telescope National Facility (ATNF) Catalogue
(Manchester et al. 2005AJ....129.1993M 2005AJ....129.1993M;
http://www.atnf.csiro.au/research/pulsar/psrcat/).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Cordes et al. Paper I. 2006ApJ...637..446C 2006ApJ...637..446C
Lorimer et al. Paper II. 2006ApJ...640..428L 2006ApJ...640..428L
Swiggum et al. Paper III. 2014ApJ...787..137S 2014ApJ...787..137S
(End) Emmanuelle Perret [CDS] 04-Feb-2016