3C 345 multiwavelength SED

Names and position

Also known as 1FGL J1642.5+3947, 1FLAT J164258.8+394837, 1Jy 1641+399, 2E 1641.2+3954, 2FGL J1642.9+3949, 3C345.0, 3FGL J1642.9+3950, 5BZQ J1642+3948, BZQ J1642+3948, CRATES J164258+394842, ROXA J164319.2+213105.9, S41641+399, TXS 1641+399, WMAP35, WMAP5 J0555+3942.

• Class: FSRQ
• Redshift: z = 0.593
• Position (ICRS): RA 250.74504°, Dec 39.81028°
• Galactic: l 63.455°, b 40.949°

Other names and measurements: NED and SIMBAD within 5″ of this position.

The SED

• Data: 8,738 points (7 upper limits) from 46 catalogues
• Dated data: 1999–2025 (MJD 51228–60948)
• Undated catalogue values: 641
• Frequency range of detections: log ν = 7.4–25.5 [Hz] (radio, microwave, infrared, optical, ultraviolet, X-ray, γ-ray)
• Swift measurements analysed by MMDC: 524 UVOT and 385 XRT
• Largest catalogues (points): ZTF (4,475), ASAS-SN (1,317), MMDCXRT_ORBIT (506), MMDCGR (371), ALMA (339)

Data by band

All 7 bands have data. The infrared band has the most points, 4,783 of 8,738; its largest catalogue is ZTF with 4,475.

Get the data

• The SED as CSV from the MMDC SED API (docs.mmdc.am).
• In Python, with astro-mmdc:

  from astro_mmdc import MMDC
  sed = MMDC().sed.get(ra=250.74504, dec=39.81028, name="3C 345")

• The interactive SED plot, with time filtering and modeling (needs JavaScript).

Nearby sources

• Mrk 501, 2.1° away
• 4C +38.41, 2.2° away
• B3 1659+399, 3.5° away
• B3 1615+412, 5.1° away

Other FSRQs

• B3 1708+433
• B2 1606+40
• 4C +47.44
• OS 319
• TXS 1629+495
• S4 1726+45

How to cite

Sahakyan, N., Vardanyan, V., Giommi, P., et al. 2024, AJ, 168, 289, doi:10.3847/1538-3881/ad8231 (arXiv:2410.01207).