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ATEL # 1694; P. E. Nugent (LBL), S. G. Djorgovski, E. Glikman, A. Mahabal (Caltech), C. Baltay, D. Rabinowitz (Yale), on behalf or the LBL Nearby Supernova Factory and Palomar-Quest survey teams
on 4 Sep 2008; 2:20 UT
Distributed as an Instant Email Notice (Transients)
Password Certification: S. George Djorgovski (email@example.com)
Subjects: Optical, Request for Observations, AGN, Quasars, Transients
Referred to by ATEL #: 1695
A number of highly variable or transient objects, not classified as likely supernovae, have been found in the course of LBL Nearby Supernova Factory processing of the Palomar-Quest (PQ) survey data over the past month. A number of these have radio source counterparts listed in NED:
Name | RA(2000) | Dec(2000) | %Incr. | Radio source
SNF20080822-002 | 00:03:59.208 | +08:41:38.40 | 286 | NVSS J000359+084137
SNF20080815-023 | 00:48:02.592 | +22:35:24.36 | 194 | GB6 J0048+2234, MG3, 87GB, NVSS
SNF20080825-007 | 00:58:32.064 | +33:11:17.53 | 832 | GB6 J0058+3311, MG3, 87GB, WB92, NVSS, etc.
SNF20080817-011 | 01:14:51.408 | +26:23:21.84 | 361 | NVSS J011451+262320
SNF20080813-014 | 01:24:50.448 | -06:25:00.48 | 247 | NVSS, PMN J0124-0624
SNF20080822-006 | 02:39:45.432 | -02:34:40.08 | 434 | PMN J0239-0234, PKS, NVSS, TXS, etc., z=1.116; P200 spec.
SNF20080817-015 | 16:53:29.924 | +31:07:57.00 | 18 | MG2, MG3, 87GB, WB92, FIRST, JVAS, etc., SDSS QSO z=1.298
SNF20080821-002 | 17:16:13.196 | +45:34:47.28 | 144 | NVSS J171613+453445; P200 spec.
SNF20080802-007 | 17:20:13.776 | +31:35:30.48 | 245 | 87GB 1718+3138, FIRST
SNF20080822-009 | 21:16:31.612 | -04:53:01.32 | 541 | NVSS J211631-045257
SNF20080801-002 | 21:20:48.459 | -03:30:28.44 | 27 | PMN J2120-0330, WB92
SNF20080806-003 | 22:00:54.863 | -16:32:32.28 | 203 | PMN J2200-1632, PKS, TXS
SNF20080823-010 | 22:50:44.469 | -28:06:38.52 | 126 | PMN J2250-2806, TXS
SNF20080823-004 | 22:52:44.083 | -23:42:45.36 | 40 | NVSS J225243-234251
The source names indicate the transient detection UT date, e.g., Aug. 22, 2008 UT for SNF20080822-002. "%Incr." gives the observed flux percentage increment, relative to the averaged baseline images obtained in the timeframe ~ 2000-2003, effectively in a broad red bandpass.
Spectra of SNF20080822-006 (0239-0234) and SNF20080821-002 (1716+4534) have been obtained at the Palomar 200-inch telescope using the Double Beam Spectrograph on 31 August 2008 UT, in variable conditions. The spectrum of SNF20080821-002 was cut by clouds, yielding no useful information.
In all cases, if more than one frequency data point is available, the radio spectra appear flat. Thus, these objects are likely blazars (or closely related flat-spectrum radio-loud quasars), undergoing an optical flaring activity. A search for correlated gamma-ray or radio flares and additional optical monitoring would be worthwhile.
PQ Survey Blazars Page