LOTAAS Pulsar Discoveries — 74  (LOFAR pulsar total — 81)


Extended table

LOTAAS confirmed discoveries
#PulsarP (ms)DM (pc/cc)Discovery date
74J1958+21105087.7Sep 2, 2019
73J0827+531323.1Nov 28, 2018
72J1333+0991123.9Aug 20, 2018
71J1303+3839619.0Jul 23, 2018
70J1706+3515919.2May 23, 2018
69J2022+2180373.5May 3, 2018
68J0813+2253152.2Apr 21, 2018
67J1910+5634120.7Jan 11, 2018
66J2123+361294108.4Dec 16, 2017
65J1953+30127143.6Dec 15, 2017
64J0100+69114563.5Dec 5, 2017
63J1426+5299525.3Oct 5, 2017
62J1958+5631158.1Sep 27, 2017
61J0210+58176676.8Sep 22, 2017
60J1017+3045227.3Aug 28, 2017
59J2034+6650150.7Aug 15, 2017
58J0107+13119721.6Aug 13, 2017
57J0249+582353545.7Aug 7, 2017
56J1657+32157023.9Jun 29, 2017
55J1740+3882847.2Jun 27, 2017
54J1638+4076733.3Jun 24, 2017
53J2122+245418.4Jun 1, 2017
52J0059+80149355.7May 30, 2017
51J1745+12105965.9May 17, 2017
50J1642+12109935.7Mar 16, 2017
49J1710+7843237.0Feb 6, 2017
48J1810+0630779.4Jan 22, 2017
47J1749+5943645.0Jan 5, 2017
46J1658+36333.0Dec 24, 2016
45J0454+45138920.8Dec 22, 2016
44J1957+0096538.3Dec 12, 2016
43J1624+5865126.4Dec 7, 2016
42J1655+6277635.3Dec 2, 2016
41J1916+32113784.2Nov 25, 2016
40J0421+3290076.9Nov 4, 2016
39J2329+4772843.9Sep 12, 2016
38J1634+23120837.5Sep 9, 2016
37J0121+14138817.8Jul 8, 2016
36J1404+11265018.5Jul 6, 2016
35J0139+33124821.2Jul 5, 2016
34J1932+53205233.4Jun 22, 2016
33J0742+4360636.1May 17, 2016
32J0856+3324223.9May 13, 2016
31J0114+6352165.0May 3, 2016
30J0518+5191239.3Mar 20, 2016
29J0349+23242163.1Mar 8, 2016
28J1849+2651974.9Jan 28, 2016
27J2051+1255343.4Jan 25, 2016
26J1340+65139430.0Jan 18, 2016
25J1235–02359718.8Jan 18, 2016
24J1225+00228418.5Jan 18, 2016
23J1733+6351041.8Aug 30, 2015
22J0039+3553653.0Aug 18, 2015
21J1745+4230537.9Aug 17, 2015
20J1715+4654819.8Aug 14, 2015
19J1726+3482123.9Aug 12, 2015
18J0928+30104521.9Aug 10, 2015
17J2053+1711927.0Jul 16, 2015
16J0810+37124816.9Jul 15, 2015
15J2006+221741130.4Jul 14, 2015
14J1740+27105835.5Jun 24, 2015
13J2210+21177646.3May 15, 2015
12J0301+20120719.0Apr 2, 2015
11J1849+15223377.4Mar 19, 2015
10J2305+3134146.1Dec 9, 2014
9J1814+2225362.3Sep 1, 2014
8J2336–01102919.6Aug 22, 2014
7J2057+21111673.6Aug 9, 2014
6J0305+1186227.8Aug 9, 2014
5J0317+13197412.9Aug 9, 2014
4J1809+17206647.0Jun 11, 2014
3J2350+3150839.1May 22, 2014
2J0935+3396118.4Mar 3, 2014
1J1529+404766.6Feb 26, 2014
 
LOTAAS non-confirmed (yet) candidates
#PulsarP (ms)DM (pc/cc)Discovery date
8J0215+5138418.4Oct 2, 2016
7J0418+22455.6Jul 5, 2016
6J1011+1829117.7Aug 20, 2018
5J1342+6512238.7Jan 22, 2016
4J1703+0063810.3Aug 7, 2018
3J1838+0012798.2Aug 26, 2017
2J2025+316.313.6Apr 22, 2016
1J2354+4038720.5Oct 2, 2016
 
LOFAR targeted searches for pulsars
#PulsarP (ms)DM (pc/cc)Discovery date
7J1158+62247.8815.0Jan 4, 2021
6J1602+39013.717.2Apr 10, 2020
5J1049+582272712.3Aug 19, 2019
4J0652+474.7525.5Dec 28, 2016
3J0815+461143411.3Dec 15, 2014
2J0952-06071.4122.4Dec 29, 2016
1J1552+54362.4222.9Mar 20, 2016
 
LOTAS pilot survey (LOTAAS predecessor)
#PulsarP (ms)DM (pc/cc)Discovery date
2J0140+561775101.6Jan 14, 2013
1J0613+3761919.1Jan 14, 2013

LOTAAS is the LOFAR Tied-Array All-Sky Survey, an ongoing LOFAR all-Northern-sky survey. LOTAAS uses the 12 HBA sub-stations on the Superterp because these give the highest filling factor of any set of stations in the array and hence the best balance of FoV and raw sensitivity. This compact configuration also completely removes the need to compensate for differential ionospheric phase delays. Each LOTAAS survey pointing (see Figure below) is comprised of three sub-array pointings (i.e. three beams generated at station level). An incoherent array beam is generated for each of these sub-array pointings, and together these cover ∼30 square degrees of sky (towards Zenith) at a sensitivity roughly twice that of our all-sky pilot commissioning survey (Coenen 2013). Within the FoV of each incoherent beam we also form a Nyquist-sampled, hexagonal grid of 61 tied-array beams. Together, this set of 3×61 tied-array beams cover a survey area of ∼10 square degrees at a sensitivity roughly twice that of the ongoing GBNCC survey. Lastly, for each sub-array pointing an additional 12 tied-array pointings are generated and pointed towards any other cataloged pulsars that fall within the incoherent FoV but outside the hexagonal grid of tied-array beams used for surveying. These additional beams provide valuable data on known sources, simultaneous with the survey observations. All together, there are 3×61+3×12+3 = 222 beams per survey pointing. In other words, this is a pulsar and fast transient survey approach unlike any other and a unique stepping stone on the path to surveying with SKA-Low. With a bandwidth of 32 MHz, a spectral resolution of 12 kHz, and a sampling time of 492 μs, LOTAAS generates data at an astounding rate of 35 Gbps (close to the total possible system throughput of the LOFAR CEP2 network). Each 1-hour pointing produces 16 TB of raw data.



Left. A single LOTAAS pointing showing the 3 groups of 61 tied-array beams each (hexagonal clusters of small circles) and the 3 incoherent beams (large circles). For simplicity, the additional 12 manually specified tied-array beams, which are pointed towards known sources in the field, are not shown. Right. Multiple interleaved LOTAAS pointings showing how dense coverage of the sky is achieved.


Sky coverage:


As of May 8, 2016 all 651 LOTAAS pointings in the Pass A are completed (1st sparse coverage). In the Pass B as of March 5, 2018 there are already 650 pointings completed (1 is still left as of Oct 5, 2018). We are almost done with the Pass C, where we already completed 589 pointings with 62 pointings to go as of October 5, 2018. In addition to that to complete the survey there are about ~50 pointings which are needed to be re-observed due to various problems.


LOTAAS complete pointings for Pass A (Hammer projection):

LOTAAS complete pointings for Pass B (Hammer projection):

LOTAAS complete pointings for Pass C (Hammer projection):


LOTAAS minimum theoretical flux:




Minimum theoretical flux of Superterp at DM = 50 and DM = 300 pc/cc, for low (solid lines) and high (dashed lines) Galactic latitudes. This includes a scattering term based on Bhat et al. (2004). The fluxes of known pulsars so far found within the LOTAAS survey (red) and LOTAAS discoveries (blue stars) are also plotted. This shows that we are within a factor of 3 in terms of reaching the theoretical survey sensitivity, and will have to dig deeper into our existing search candidate lists to find the weakest sources.


Publications:


6. Michilli, D. et al. 2018, Single-pulse classifier for the LOFAR Tied-Array All-sky Survey, MNRAS, 480, 3457
5. Tan, C. M. et al. 2018, LOFAR discovery of a 23.5-second radio pulsar, ApJ, accepted
4. Tan, C. M. et al. 2018, Ensemble candidate classification for the LOTAAS pulsar survey, MNRAS, 474, 4571
3. Tan, C. M. et al. 2018, The LOFAR Tied-Array All-Sky Survey for Pulsars and Fast Transients, "Pulsar Astrophysics the Next Fifty Years", IAU Symposium, 337, pp. 9-12
2. Coenen, T. et al. 2014, The LOFAR pilot surveys for pulsars and fast radio transients, A&A, 570, 60
1. Coenen, T. 2013, Searching for pulsars with LOFAR, PhD thesis, University of Amsterdam; (Pilot surveys, LPPS and LOTAS)


LOFAR Pulsar Working Group members:


Jason Hessels (co-lead, ASTRON/UvA)
Ben Stappers (co-lead, University of Manchester)
Anya Bilous (RU Nijmegen)
Thijs Coenen (UvA)
Sally Cooper (University of Manchester)
Heino Falcke (RU Nijmegen)
Jean-Mathias Griessmeier (LPC2E/CNRS/Universite d'Orleans)
Tom Hassall (University of Southampton)
Aris Karastergiou (University of Oxford)
Evan Keane (Swinburne University of Technology)
Vlad Kondratiev (ASTRON)
Michael Kramer (MPIfR)
Masaya Kuniyoshi (MPIfR)
Joeri van Leeuwen (ASTRON/UvA)
Aris Noutsos (MPIfR)
Maura Pilia (ASTRON)
Maciej Serylak (University of Oxford)
Charlotte Sobey (ASTRON)
Sander ter Veen (RU Nijmegen)
Joris Verbiest (Universitat Bielefeld)
Patrick Weltevrede (University of Manchester)
Kimon Zagkouris (University of Oxford)


Other pulsar surveys:

Known FRBs:



The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement nr. 337062 (DRAGNET; PI Hessels) and from an NWO Vidi Fellowship (PI Hessels).