J/A+A/305/74 J/A+A/305/74 NGC 4565, 4656 & 5907 ROSAT observations A Vogler W Pietsch P T Kahabka Astron. Astrophys. 305 74 1996 1996A&A...305...74V IX/11 : ROSAT Source Catalog (Voges+ 1994) Galaxies, optical X-ray sources galaxies: individual (NGC 4565, NGC 4656, NGC 5907) galaxies: spiral X-rays: galaxies The edge-on spiral galaxies NGC 4565, NGC 4656, and NGC 5907 have been observed with the PSPC onboard ROSAT. The targets were selected for low galactic foreground absorption to enable the detection of "soft" X-ray emission, which is a fingerprint for the emission of a million degree gaseous component. For NGC 4565 we find an X-ray luminosity of 1.1x10^40^erg/s . Point sources contribute 6.0x10^39^erg/s in the bulge and 0.7x10^39^erg/s in the disk. 1.2x10^39^erg/s may be due to diffuse X-ray emission in the bulge or disk. A nuclear source (L_x_=2.7x10^39^erg/s) is visible. In the halo of NGC 4565 diffuse emission with a luminosity of 2.6x10^39^erg/s was detected. The X-ray data indicate low absorption and soft spectra. Attributing the entire diffuse flux to emission of a hot thermal plasma, its density, mass, and cooling time are n=0.6x10^-3cm^-3/sqrt({eta}), m=2.2x10^7^Ms_{sun}_.sqrt({eta}) and {tau}=4.2x10^8^y.sqrt({eta}), respectively (with the filling factor {eta}). The disturbed galaxy NGC 4656 shows a luminosity of 1.5x10^39^erg/s, composed of a weak nuclear point source (L_x_=1.3x10^38^erg/s), five further point sources in the disk (L_x_=1.0x10^39^erg/s), and remaining diffuse emission components (L_x_=0.3x10^39^erg/s). No diffuse emission could be established in the halo of NGC 4656. NGC 5907 has an overall X-ray luminosity of 6.5x10^39^erg/s. The only point source in the bulge coincides with the nucleus (L_x_=2.8x10^39^erg/s), three point sources in the disk show an integral luminosity of 3.2x10^39^erg/s. Neither X-ray emission from SN 1940a in NGC 5907 nor diffuse halo emission could be found. The different X-ray components for the three galaxies are discussed and compared to results from other wavelength regimes.

ROSAT NGC 456512 36.3 +25 58 NGC 465612 44.2 +32 12 NGC 590715 15.9 +56 19

Field Field designation --- Name Source name --- RAh Rights ascension (2000) h RAm Rights ascension (2000) min RAs Rights ascension (2000) s DE- Declination sign --- DEd Declination (2000) deg DEm Declination (2000) arcmin DEs Declination (2000) arcsec e_Pos rms uncertainty on position arcsec L(Exist) Likelihood of existence ---- Counts Net counts in the ROSAT 0.1-2.4keV band ct e_Counts rms uncertainty on Counts number=1 In table 17, in the printed version, Counts for A43 is 29.8 +/- -9.2. In electronic table17, we transform e_Counts=-9.2 to 9.2 ct HR1 Hard ratio 1 --- HR2 Hard ratio 2 --- Rate Count rate for the 0.1-2.4keV band 10-3ct/s e_Rate rms uncertainty on Rate 10-3ct/s FWHMExt FWHM of the extent number=2 FWHM and likelihood of extent for sources for which the extent exceeds the PSPC PRF and for which the likelihood of extent is >=9. arcsec lExt Likelihood of extent number=2 FWHM and likelihood of extent for sources for which the extent exceeds the PSPC PRF and for which the likelihood of extent is >=9. --- Source Source name --- Candidate Candidate --- Err Distance of X-ray detection number=1 Distance of X-ray detection and proposed identification in arcsec, including a 4" systematical error of the X-ray position, no error quoted for extended objects. arcsec Err2 Second value of Err (for A27 only) arcsec Ref References number=2 References: PI,PII first and second PALOMAR survey GC Gregory & Condon (1991ApJS...75.1011G) GSC guide star catalogue from EXOSAT database, Astrophysics Division at ESTEC SIM SIMBAD catalogue, MPE database HB Hewett & Burbridge (1989, A new Catalog of Quasi-Stellar Objects, stored on magnetic tape 1989) MB Mazarella & Balzano (1986ApJS...62..751M) --- James Marcout, Patricia Bauer CDS 1997Apr11 UNKNOWN UNKNOWN Prepared via OCR at CDS. J_A+A_305_74.xml