# | Pulsar | P (ms) | DM (pc/cc) | Discovery date |
15 | J2006+22 | 1741 | 130.4 | Jul 14, 2015 |
66 | J2123+36 | 1294 | 108.4 | Dec 16, 2017 |
74 | J1958+21 | 1050 | 87.7 | Sep 2, 2019 |
41 | J1916+32 | 1137 | 84.2 | Nov 25, 2016 |
48 | J1810+06 | 307 | 79.4 | Jan 22, 2017 |
11 | J1849+15 | 2233 | 77.4 | Mar 19, 2015 |
40 | J0421+32 | 900 | 76.9 | Nov 4, 2016 |
61 | J0210+58 | 1766 | 76.8 | Sep 22, 2017 |
28 | J1849+26 | 519 | 74.9 | Jan 28, 2016 |
7 | J2057+21 | 1116 | 73.6 | Aug 9, 2014 |
69 | J2022+21 | 803 | 73.5 | May 3, 2018 |
51 | J1745+12 | 1059 | 65.9 | May 17, 2017 |
31 | J0114+63 | 521 | 65.0 | May 3, 2016 |
64 | J0100+69 | 1145 | 63.5 | Dec 5, 2017 |
29 | J0349+23 | 2421 | 63.1 | Mar 8, 2016 |
9 | J1814+22 | 253 | 62.3 | Sep 1, 2014 |
62 | J1958+56 | 311 | 58.1 | Sep 27, 2017 |
52 | J0059+80 | 1493 | 55.7 | May 30, 2017 |
22 | J0039+35 | 536 | 53.0 | Aug 18, 2015 |
68 | J0813+22 | 531 | 52.2 | Apr 21, 2018 |
59 | J2034+66 | 501 | 50.7 | Aug 15, 2017 |
55 | J1740+38 | 828 | 47.2 | Jun 27, 2017 |
4 | J1809+17 | 2066 | 47.0 | Jun 11, 2014 |
13 | J2210+21 | 1776 | 46.3 | May 15, 2015 |
10 | J2305+31 | 341 | 46.1 | Dec 9, 2014 |
57 | J0249+58 | 23535 | 45.7 | Aug 7, 2017 |
47 | J1749+59 | 436 | 45.0 | Jan 5, 2017 |
39 | J2329+47 | 728 | 43.9 | Sep 12, 2016 |
65 | J1953+30 | 1271 | 43.6 | Dec 15, 2017 |
27 | J2051+12 | 553 | 43.4 | Jan 25, 2016 |
23 | J1733+63 | 510 | 41.8 | Aug 30, 2015 |
30 | J0518+51 | 912 | 39.3 | Mar 20, 2016 |
3 | J2350+31 | 508 | 39.1 | May 22, 2014 |
44 | J1957+00 | 965 | 38.3 | Dec 12, 2016 |
21 | J1745+42 | 305 | 37.9 | Aug 17, 2015 |
38 | J1634+23 | 1208 | 37.5 | Sep 9, 2016 |
49 | J1710+78 | 432 | 37.0 | Feb 6, 2017 |
33 | J0742+43 | 606 | 36.1 | May 17, 2016 |
50 | J1642+12 | 1099 | 35.7 | Mar 16, 2017 |
14 | J1740+27 | 1058 | 35.5 | Jun 24, 2015 |
42 | J1655+62 | 776 | 35.3 | Dec 2, 2016 |
34 | J1932+53 | 2052 | 33.4 | Jun 22, 2016 |
54 | J1638+40 | 767 | 33.3 | Jun 24, 2017 |
26 | J1340+65 | 1394 | 30.0 | Jan 18, 2016 |
6 | J0305+11 | 862 | 27.8 | Aug 9, 2014 |
60 | J1017+30 | 452 | 27.3 | Aug 28, 2017 |
17 | J2053+17 | 119 | 27.0 | Jul 16, 2015 |
43 | J1624+58 | 651 | 26.4 | Dec 7, 2016 |
63 | J1426+52 | 995 | 25.3 | Oct 5, 2017 |
72 | J1333+09 | 911 | 23.9 | Aug 20, 2018 |
56 | J1657+32 | 1570 | 23.9 | Jun 29, 2017 |
32 | J0856+33 | 242 | 23.9 | May 13, 2016 |
19 | J1726+34 | 821 | 23.9 | Aug 12, 2015 |
73 | J0827+53 | 13 | 23.1 | Nov 28, 2018 |
18 | J0928+30 | 1045 | 21.9 | Aug 10, 2015 |
58 | J0107+13 | 1197 | 21.6 | Aug 13, 2017 |
35 | J0139+33 | 1248 | 21.2 | Jul 5, 2016 |
45 | J0454+45 | 1389 | 20.8 | Dec 22, 2016 |
67 | J1910+56 | 341 | 20.7 | Jan 11, 2018 |
20 | J1715+46 | 548 | 19.8 | Aug 14, 2015 |
8 | J2336–01 | 1029 | 19.6 | Aug 22, 2014 |
70 | J1706+35 | 159 | 19.2 | May 23, 2018 |
71 | J1303+38 | 396 | 19.0 | Jul 23, 2018 |
12 | J0301+20 | 1207 | 19.0 | Apr 2, 2015 |
25 | J1235–02 | 3597 | 18.8 | Jan 18, 2016 |
36 | J1404+11 | 2650 | 18.5 | Jul 6, 2016 |
24 | J1225+00 | 2284 | 18.5 | Jan 18, 2016 |
2 | J0935+33 | 961 | 18.4 | Mar 3, 2014 |
37 | J0121+14 | 1388 | 17.8 | Jul 8, 2016 |
16 | J0810+37 | 1248 | 16.9 | Jul 15, 2015 |
5 | J0317+13 | 1974 | 12.9 | Aug 9, 2014 |
53 | J2122+24 | 541 | 8.4 | Jun 1, 2017 |
1 | J1529+40 | 476 | 6.6 | Feb 26, 2014 |
46 | J1658+36 | 33 | 3.0 | Dec 24, 2016 |
LOTAAS non-confirmed (yet) candidates | ||||
# | Pulsar | P (ms) | DM (pc/cc) | Discovery date |
8 | J0215+51 | 384 | 18.4 | Oct 2, 2016 |
7 | J0418+22 | 45 | 5.6 | Jul 5, 2016 |
6 | J1011+18 | 291 | 17.7 | Aug 20, 2018 |
5 | J1342+65 | 122 | 38.7 | Jan 22, 2016 |
4 | J1703+00 | 638 | 10.3 | Aug 7, 2018 |
3 | J1838+00 | 127 | 98.2 | Aug 26, 2017 |
2 | J2025+31 | 6.3 | 13.6 | Apr 22, 2016 |
1 | J2354+40 | 387 | 20.5 | Oct 2, 2016 |
LOFAR targeted searches for pulsars | ||||
# | Pulsar | P (ms) | DM (pc/cc) | Discovery date |
7 | J1158+6224 | 7.88 | 15.0 | Jan 4, 2021 |
6 | J1602+3901 | 3.7 | 17.2 | Apr 10, 2020 |
5 | J1049+5822 | 727 | 12.3 | Aug 19, 2019 |
4 | J0652+47 | 4.75 | 25.5 | Dec 28, 2016 |
3 | J0815+4611 | 434 | 11.3 | Dec 15, 2014 |
2 | J0952-0607 | 1.41 | 22.4 | Dec 29, 2016 |
1 | J1552+5436 | 2.42 | 22.9 | Mar 20, 2016 |
LOTAS pilot survey (LOTAAS predecessor) | ||||
# | Pulsar | P (ms) | DM (pc/cc) | Discovery date |
2 | J0140+56 | 1775 | 101.6 | Jan 14, 2013 |
1 | J0613+37 | 619 | 19.1 | Jan 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.
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.
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).