NGC2547XMM - NGC 2547 XMM-Newton X-Ray Point Source Catalog

Overview

This table contains a list of point sources detected by XMM-Newton EPIC in a pointing towards the young open cluster NGC 2547, made in order to allow the authors to characterize coronal activity in solar-type stars, and stars of lower mass, at an age of 30 Myr. X-ray emission was seen from stars at all spectral types, peaking among G stars at luminosities (0.3 - 3 keV) of L_x ~= 10^30.5 erg/s and declining to L_x <= 10²⁹ erg/s among M stars with masses >=0.2 solar masses. Coronal spectra show evidence for multi-temperature differential emission measures and low coronal metal abundances of Z~= 0.3. Most of the solar-type stars in NGC 2547 exhibit saturated or even supersaturated X-ray activity levels. The median levels of L_x and L_x/L_bol in the solar-type stars of NGC 2547 are very similar to those in T-Tauri stars of the Orion Nebula cluster (ONC), but an order of magnitude higher than in the older Pleiades. The spread in X-ray activity levels among solar-type stars in NGC 2547 is much smaller than in older or younger clusters.

This table contains the properties of those X-ray sources which are correlated with optical cluster members (see Section 2.2 of the reference paper for details on the correlation procedure that was adopted), as well as the properties of those X-ray sources which are uncorrelated with any optical cluster members. The table lists the cross-identifications with optical catalogs for the candidate cluster sources along with their X-ray luminosities and X-ray to bolometric flux ratios, as well as the correlations between cluster members which were detected by XMM-Newton and those detected 7 years earlier by the ROSAT HRI instrument, along with the X-ray luminosities and flux ratios as determined by the HRI.

Catalog Bibcode

2006MNRAS.367..781J

References

An XMM-Newton observation of the young open cluster NGC 2547:
coronal activity at 30 Myr.
    Jeffries R.D., Evans P.A., Pye J.P., Briggs K.R.
    <Mon. Not. R. Astron. Soc. 367, 781 (2006)>
    =2006MNRAS.367..781J        (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in February 2007 based on CDS Catalog J/MNRAS/367/781 files table1.dat, table2.dat, table3.dat and table7.dat.

HEASARC Implementation

The HEASARC has merged 108 X-ray sources which are correlated with photometric candidate members of NGC 2547 (whose properties are listed in Tables 1, 2 and 7 of the published paper) with 55 X-ray sources which have no cluster counterparts (whose properties are listed in Table 3 which is only available in electronic format) to produce this table of 163 detected X-ray sources in the field of NGC 2547. To clearly differentiate sources from the two tables, the HEASARC has created a new parameter called cluster_member which is set to 'Y' for Table 1 sources and to 'N' for Table 3 sources.

Parameters

Source_Number
A running source identification number, as produced by the XMM-Newton Science Analysis System (SAS).

Name
The conventional XMM-Newton source name using the standard 'XMMU' prefix.

Cluster_Member
The HEASARC has merged 108 X-ray sources which are correlated with photometric candidate members of NGC 2547 (listed in Table 1 of the published paper) with 55 X-ray sources which have no cluster counterparts (listed in Table 3 and only available in electronic format) to produce this table of 163 X-ray sources. To clearly differentiate sources from the two tables, the HEASARC has created this parameter which is set to 'Y' for Table 1 sources and to 'N' for Table 3 sources.

Alt_Name
An alternative name for the XMM-Newton X-ray source using the '[JEP2006]' prefix (for Jeffries, Evans and Pye 2006) and the source number, as recommended by the CDS Dictionary of Nomenclature of Celestial Objects.

RA
The Right Ascension of the X-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.01 seconds of time in the original tables. An astrometric correction of -1.48" in RA was applied to the original XMM-Newton values in order to bring them into the optical reference frame.

Dec
The Declination of the X-ray source in the selected equinox. This was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the original tables. An astrometric correction of -0.05" in Declination was applied to the original XMM-Newton values in order to bring them into the optical reference frame.

LII
The Galactic Longitude of the X-ray source.

BII
The Galactic Latitude of the X-ray source.

Error_Radius
The one-sigma positional error of the X-ray source, in arcseconds, corrected for a mean astrometric shift and including an additional systematic error of 1.2" added in quadrature. See Section 2.2 of the reference paper for more details.

ML_Statistic
The maximum likelihood statistic ML for the X-ray source returned by the SAS analysis. The EDETECT_CHAIN task was used to find sources with a combined ML value in all 3 EPIC instruments greater than 10 for the 0.3 - 3.0 keV energy range. With this threshold, 1-2 spurious detections are expected, although they would be highly unlikely to correlate with an NGC 2547 member's position.

PN_Count_Rate
The PN count rate of the X-ray source in the total band (0.3 - 3 keV), in ct/s.

PN_Count_Rate_Error
The uncertainty in the PN total-band count rate, in ct/s.

PN_SB_Count_Rate
The PN count rate of the X-ray source in the soft band (0.3 - 1.0 keV), in ct/s.

PN_SB_Count_Rate_Error
The uncertainty in the PN soft-band count rate, in ct/s.

PN_HB_Count_Rate
The PN count rate of the X-ray source in the hard band (1.0 - 3 keV), in ct/s.

PN_HB_Count_Rate_Error
The uncertainty in the PN hard-band count rate, in ct/s.

PN_Hardness_Ratio
The hardness ratio HR of the X-ray source in the PN, defined as HR = (H-S)/(H+S), where H is the hard-band counts and S is the soft-band counts measured by this instrument.

PN_Hardness_Ratio_Error
The uncertainty in the PN hardness ratio for the X-ray source.

M1_Count_Rate
The MOS1 count rate of the X-ray source in the total band (0.3 - 3 keV), in ct/s.

M1_Count_Rate_Error
The uncertainty in the MOS1 total-band count rate, in ct/s.

M1_SB_Count_Rate
The MOS1 count rate of the X-ray source in the soft band (0.3 - 1.0 keV), in ct/s.

M1_SB_Count_Rate_Error
The uncertainty in the MOS1 soft-band count rate, in ct/s.

M1_HB_Count_Rate
The MOS1 count rate of the X-ray source in the hard band (1.0 - 3 keV), in ct/s.

M1_HB_Count_Rate_Error
The uncertainty in the MOS1 hard-band count rate, in ct/s.

M1_Hardness_Ratio
The hardness ratio HR of the X-ray source in the MOS1, defined as HR = (H-S)/(H+S), where H is the hard-band counts and S is the soft-band counts measured by this instrument.

M1_Hardness_Ratio_Error
The uncertainty in the MOS1 hardness ratio for the X-ray source.

M2_Count_Rate
The MOS2 count rate of the X-ray source in the total band (0.3 - 3 keV), in ct/s.

M2_Count_Rate_Error
The uncertainty in the MOS2 total-band count rate, in ct/s.

M2_SB_Count_Rate
The MOS2 count rate of the X-ray source in the soft band (0.3 - 1.0 keV), in ct/s.

M2_SB_Count_Rate_Error
The uncertainty in the MOS2 soft-band count rate, in ct/s.

M2_HB_Count_Rate
The MOS2 count rate of the X-ray source in the hard band (1.0 - 3 keV), in ct/s.

M2_HB_Count_Rate_Error
The uncertainty in the MOS2 hard-band count rate, in ct/s.

M2_Hardness_Ratio
The hardness ratio HR of the X-ray source in the MOS2, defined as HR = (H-S)/(H+S), where H is the hard-band counts and S is the soft-band counts measured by this instrument.

M2_Hardness_Ratio_Error
The uncertainty in the MOS2 hardness ratio for the X-ray source.

NTJ_Identifier
The identifier (NN NNNN) used by Naylor et al. (2002, CDS Cat. <J/MNRAS/335/291> = NTJ) for the candidate cluster star identified as the optical counterpart to the X-ray source. Such stars are identified as 'Cl* NGC 2547 NTJ NN-NNNN' in Simbad.

Offset_NTJ_XMM
The separation between the XMM source position and the position of the NTJ counterpart star, in arcseconds.

Vmag
The apparent V magnitude (Johnson) of the star identified as the optical counterpart to the X-ray source, as given by Naylor et al. (2002, CDS Cat. <J/MNRAS/335/291>).

BV_Color
The B-V color index (Johnson) of the star identified as the optical counterpart to the X-ray source, as given by Naylor et al. (2002, CDS Cat. <J/MNRAS/335/291>).

VI_Color
The V-I_c color index (Johnson-Cousins) of the star identified as the optical counterpart to the X-ray source, as given by Naylor et al. (2002, CDS Cat. <J/MNRAS/335/291>).

JND_Identifier
The identifier (FF NNNN) used by Jeffries et al. (2004, MNRAS, 351, 1401 = JND) for the candidate cluster star identified as the optical counterpart to the X-ray source. Such stars are identified as 'Cl* NGC 2547 JND FF-NNNN' in Simbad.

Offset_JND_XMM
The separation between the XMM source position and the position of the JND counterpart star, in arcseconds.

Imag
The apparent I magnitude (Cousins) of the star identified as the optical counterpart to the X-ray source, as given by Jeffries et al. (2004, MNRAS, 351, 1401 = JND).

RI_Color
The R_c-I_c (Cousins) color index of the star identified as the optical counterpart to the X-ray source, as given by Jeffries et al. (2004, MNRAS, 351, 1401 = JND).

Lx_Lbol_BV
The X-ray (0.3 - 3 keV) to bolometric luminosity ratio for the X-ray source and its cluster candidate counterpart, calculated using the bolometric correction derived from the B-V color index.

Lx_Lbol_VI
The X-ray (0.3 - 3 keV) to bolometric luminosity ratio for the X-ray source and its cluster candidate counterpart, calculated using the bolometric correction derived from the V-I_c color index.

Lx_Lbol_RI
The X-ray (0.3 - 3 keV) to bolometric luminosity ratio for the X-ray source and its cluster candidate counterpart, calculated using the bolometric correction derived from the R_c-I_c color index.

Lx
The X-ray luminosity in the total band (0.3 - 3 keV) for the X-ray source, in erg/s, assuming a distance to NGC 2547 of 417 pc.

Lx_Error
The 1-sigma uncertainty in the total-band X-Ray luminosity, in erg/s.

HRI_Identifier
The RX identifier for the counterpart ROSAT HRI source used by Jeffries & Tolley (1998 MNRAS, 300, 331). The correlation of the XMM-Newton sources with the HRI sources was done only for those XMM-Newton sources which have candidate cluster star counterparts (i.e., entries which have cluster_member = 'Y').

Offset_HRI_XMM
The separation between the XMM source position and the ROSAT HRI position, in arcseconds.

HRI_Count_Rate
The ROSAT HRI count rate, in ct/s, modified from the Jeffries & Tolley (1998 MNRAS, 300, 331) value as explained in Section 5.2 of the reference paper.

HRI_Count_Rate_Error
The uncertainty in the ROSAT HRI count rate, in ct/s.

HRI_Count_Rate_Limit
This parameter is set to '<' if the quoted HRI count rate is an upper limit rather than a detection.

HRI_Lx_Lbol_BV
The X-ray (0.3 - 3 keV) to bolometric luminosity ratio for the HRI source and its cluster candidate counterpart, calculated using the bolometric correction derived from the B-V color index.

HRI_Lx_Lbol_VI
The X-ray (0.3 - 3 keV) to bolometric luminosity ratio for the HRI source and its cluster candidate counterpart, calculated using the bolometric correction derived from the V-I_c color index.

HRI_Lx_Lbol_RI
The X-ray (0.3 - 3 keV) to bolometric luminosity ratio for the HRI source and its cluster candidate counterpart, calculated using the bolometric correction derived from the R_c-I_c color index.

HRI_Lx
The ROSAT HRI X-ray luminosity computed for the same band as was used for the XMM-Newton source (0.3 - 3 keV energy range, in erg/s, assuming a distance to NGC 2547 of 417 pc.) and a conversions factor of 3.40 x 10^-11 erg/(cm²*ct). See Section 5.2 of the reference paper for more details).

Contact Person

Questions regarding the NGC2547XMM database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:31:54 EDT