a BiRD Overview

BiRD: A Browsing Interface for RGS Data

Rosario González-Riestra and Pedro M. Rodríguez-Pascual

XMM-Newton Science Operations Centre, ESAC

Introduction

BiRD is a browsing and visualization tool for XMM-Newton RGS fluxed spectra. It allows the user to browse and examine the data before downloading them from the XSA for full analysis.

The BiRD interface makes possible to select spectra through a variety of parameters, such as (e.g.) date of observation, level of exposure or type of object.

It also provides some basic visualization utilities, both for the RGS spectra and spectral images, as well as for the EPIC-pn images taken in parallel.

What is RGS?
The Reflection Grating Spectrometer in one of the instruments on-board XMM-Newton. Its purpose is to obtain high spectral resolution (from 100 to 500, FWHM) X-ray spectroscopy in the range 5-38 Å.
Two of the three XMM-Newton X-ray telescopes are equipped with RGS instruments. After the first week of operations, an electronic component of one one of the RGS2 chips failed, affecting the wavelength range from 20.0 to 24.1 Å. A similar problem occurred in early September 2000 with one of the chips of RGS1 covering 10.6 to 13.8 Å. The total effective area is thus reduced by a factor of two in these wavelength bands.
A detailed description of the characteristics and performance of the RGS instruments can be found in the XMM-Newton Handbook.
The RGS Chapter in the XMM SAS (Science Analysis System) User's Guide provides useful information about RGS data products and their analysis.
What are fluxed spectra?
RGS fluxed spectra are computed dividing the extracted spectrum by the effective area calculated from its corresponding response matrix (see the description of the SAS task rgsfluxer).
This procedure neglects the redistribution of monochromatic response into the dispersion channels, and therefore these spectra should not be used for any detailed spectral analysis of the data (e.g. measurement of line widths).
Nevertheless, fluxed spectra are extremely useful for visualizing the data free from the peculiarities of the instrument. This is especially so because of the possibility of combining data from both cameras into a single spectrum, thus eliminating many of the gaps between functioning detectors.
Fluxed spectra are given in physical units (photons/cm²/s/Å vs. Å).

Some useful links

The Reflection Grating Spectrometer on board XMM-Newton, den Herder, J.W. et al, 2001, A&A 365, L7
A technical description of the Reflection Grating Spectrometer on board XMM-Newton
XMM-Newton Users Handbook, Ness, J.U. et al., 2009
User's Guide to the XMM-Newton Science Analysis System, de la Calle et al., 2009

Processing Details

As of November 2009, 7498 ODFs were downloaded from the XMM-Newton Science Archive (XSA) and processed with SAS.

Data were processed with the SAS metatask rgsproc.
rgsproc was run using the target coordinates given in the XMM-Newton proposal
First order spectra (without background subtraction) were generated using 100% of the spatial PSF. A model background spectrum (generated with the SAS task rgsbkgmodel) was used for the background correction
Response matrices were computed for each spectrum with rgsrmfgen
Finally, a fluxed spectrum was created for each observation combining all the available RGS1 and RGS2 first order spectra with rgsfluxer

Additional Information available in BiRD

In addition to the spectra themselves, the BiRD interface provides other information that might be useful for the interpretation of the data:

Start time of the observation
Target name as provided in the XMM-Newton proposal
Target coordinates as provided in the XMM-Newton proposal
RGS effective exposure time (taken as the average of the exposure time of the RGS1 and RGS2 spectra)
An estimation of the quality of the combined RGS1+RGS2 fluxed spectrum
Galactic Hydrogen column density, obtained from Dickey and Lockman (1990)
From the SIMBAD database:
- Name
- Coordinates
- Type of object
- Redshift (if applicable)
  SIMBAD was queried to derive a first target identification and classification using the target name given in the XMM-Newton proposal as input. In the cases where a SIMBAD object could not be unambiguously selected using the target name, the procedure was done manually, examining the different identifications of nearby objects. For a number of cases, the type of object was obtained from the abstract of the scientific justification of the proposal.
  Some particular cases:
  - Survey fields have been assigned the SIMBAD Type 'Region defined in the sky'
  - Solar System objects have been assigned Types 'Planet' or 'Comet', as applicable

Some Numbers...

Object Types

The BiRD database includes 2744 different objects. Thirty two of them have been observed more than fifteen times:

Object SIMBAD Type N. of observations

M 31 LINER-type Active Galaxy Nucleus 67

EXO 0748-676 Low Mass X-ray Binary 51

Mkn 421 BL Lac - type object 47

Galactic Centre Region defined in the sky 38

N 132D SuperNova Remnant 32

AB Dor Rotationally variable Star 31

3C 273 Quasar 27

Coma Cluster Cluster of Galaxies 27

HR 1099 Variable of RS CVn type 27

Crab Pulsar 26

M 33 Galaxy 25

SNR 0102-72.3 SuperNova Remnant 25

CAL 83 X-ray Binary 22

Lockman Hole Region defined in the sky 22

AMS 16 Quasar 21

Capella Variable of RS CVn type 21

Object SIMBAD Type N. of observations

SMC Galaxy 20

Her X-1 Low Mass X-ray Binary 20

PKS 2155-304 BL Lac - type object 19

Eta Car Variable Star 19

PKS-0558-504 Seyfert 1 Galaxy 18

BPM 16274 White Dwarf 17

HD 81809 Spectroscopic binary 17

NGC 4051 Seyfert 1 Galaxy 17

Vela SuperNova Remnant 17

BPM 16274 Star 16

Chandra Deep Field-South Region defined in the sky 16

Zeta Puppis Variable of BY Dra type 16

Subaru/XMM Deep Field Region defined in the sky 16

Cygnus Loop SuperNova Remnant 16

Cas A SuperNova Remnant 16

SN 1006 SuperNova Remnant 16

These objects belong to 139 different types. SIMBAD types with more than twenty different objects are:

SIMBAD Type N. of objects N. of observations

Cluster of Galaxies 313 638

Seyfert 1 Galaxy 294 568

Quasar 175 293

Seyfert 2 Galaxy 168 241

Galaxy 166 281

SuperNova Remnant 98 325

X-ray source 90 117

Pulsar 85 254

Low Mass X-ray Binary 71 268

Radio Galaxy 65 87

Star 48 149

High Mass X-ray Binary 48 135

Cataclysmic Variable Star 47 60

LINER-type Active Galaxy Nucleus 42 146

Cataclysmic Var. AM Her type 42 75

Variable Star 38 73

High proper-motion Star 38 45

gamma-ray Burst 36 55

Interacting Galaxies 34 72

T Tau-type Star 32 60

SIMBAD Type N. of objects N. of observations

HII Galaxy 32 41

Nova 31 61

gamma-ray source 31 58

BL Lac - type object 30 124

Open (galactic) Cluster 29 48

Group of Galaxies 29 46

Region defined in the sky 26 584

Radio-source 25 37

Galaxy in Cluster of Galaxies 24 31

Wolf-Rayet Star 23 53

Dwarf Nova 23 31

White Dwarf 21 55

Galaxy in Group of Galaxies 21 34

Active Galaxy Nucleus 21 27

Variable of RS CVn type 18 75

Globular Cluster 17 33

SuperNova 17 26

Emission-line Star 16 35

Galaxy in Pair of Galaxies 16 21

Exposure Times

The median exposure time of the RGS spectra is 20 ksec. Observations longer than 125 ksec (i.e. about one revolution long) are:

ObsId Object SIMBAD Type Texp (sec)

0147440101 IC 4329A Seyfert 1 Galaxy 135369

0112210501 NGC 3783 Seyfert 1 Galaxy 134625

0204730301 GX 339-4 Low Mass X-ray Binary 134439

0606150101 QSO B1126-041 Seyfert 1 Galaxy 133892

0605540101 AWM 7 Cluster of Galaxies 133639

0147800201 ZwCl 0335+0956 Cluster of Galaxies 133509

0504370401 BL Lac BL Lac - type object 133495

0202670801 SGR A* Radio-source 133276

0604960401 Chandra Deep Field-South Region defined in the sky 133228

0555780201 Chandra Deep Field-South Region defined in the sky 132787

0202670601 SGR A* Radio-source 132741

0204730201 GX 339-4 Low Mass X-ray Binary 132679

0306870101 Mrk 335 Seyfert 1 Galaxy 132595

0300430101 NGC 3256 Interacting Galaxies 132436

0555780101 Chandra Deep Field-South Region defined in the sky 132393

0202670701 SGR A* Radio-source 132278

0302900101 NGC 5408 Emission-line galaxy 131670

0600540601 Mkn 335 Seyfert 1 Galaxy 131622

0305540701 rho Oph Star in Nebula 131262

0200370101 BP TAU T Tau-type Star 131035

0202670501 SGR A* Radio-source 130243

0504370701 QSO B2356-309 BL Lac - type object 130107

0503490201 1RXS J224322.6-093549 X-ray source 129604

0400620101 NGC 1399 Galaxy in Cluster of Galaxies 129525

0109890501 Abell 665 Cluster of Galaxies 128961

ObsId Object SIMBAD Type Texp (sec)

0555630501 SN 1006 SuperNova Remnant 128955

0505140401 NGC 1365 Seyfert 1 Galaxy 128677

0554680101 NGC 5044 Galaxy in Group of Galaxies 128349

0502290101 PSR J0030+0451 Pulsar 128288

0111800101 M 81 LINER-type Active Galaxy Nucleus 127908

0505140201 NGC 1365 Seyfert 1 Galaxy 127659

0555170301 PKS 0558-504 Seyfert 1 Galaxy 127403

0152840101 3C120 Seyfert 1 Galaxy 127355

0504780501 HCG 62 Cluster of Galaxies 126709

0501790101 NGC 2547 Cluster of Stars 126685

0300270201 XX Cha T Tau-type Star 126639

0200080701 Jupiter Planet 126621

0155960501 PSR J1210-5226 Pulsar 126405

0109141301 Mkn 766 Seyfert 1 Galaxy 126404

0101440801 SU Aur Variable Star of Orion Type 126126

0107460701 NGC 3516 Seyfert 1 Galaxy 126094

0555170401 PKS 0558-504 Seyfert 1 Galaxy 125899

0505140501 NGC 1365 Seyfert 1 Galaxy 125796

0555170501 PKS 0558-504 Seyfert 1 Galaxy 125680

0155960301 PSR J1210-5226 Pulsar 125677

0560180401 GRB 980618A gamma-ray Burst 125445

0147800101 Sersic 159-03 Cluster of Galaxies 125281

0555781001 Chandra Deep Field-South Region defined in the sky 125275

0555782301 Chandra Deep Field-South Region defined in the sky 125254

The Brightest Targets

The brightest objects observed with RGS (those having more than 25 cts/sec in the extracted RGS1 spectrum over the full wavelength range) are:

Obsid Object Type of Object cts/sec

0122330701 Crab Pulsar 233

0122330801 Crab Pulsar 232

0118700101 Crab Pulsar 226

0410180301 RS Oph Symbiotic Star 177

0312790101 Crab Pulsar 174

0202401101 Cyg X-1 High Mass X-ray Binary 173

0137550801 Crab Pulsar 171

0202401201 Cyg X-1 High Mass X-ray Binary 154

0153750401 Crab Pulsar 99

0412592601 Crab Pulsar 93

0160961501 Crab Pulsar 90

0160961201 Crab Pulsar 88

0202760201 Cyg X-1 High Mass X-ray Binary 87

0160960201 Crab Pulsar 86

0160960301 Crab Pulsar 86

0093562701 GX 339-3 Low Mass X-ray Binary 83

Obsid Object Type of Object cts/sec

0112921601 GRO J1655-40 Low Mass X-ray Binary 81

0111360201 GX 339-4 Low Mass X-ray Binary 79

0112921501 GRO J1655-40 Low Mass X-ray Binary 76

0112921401 GRO J1655-40 Low Mass X-ray Binary 75

0202760501 Cyg X-1 High Mass X-ray Binary 65

0202760401 Cyg X-1 High Mass X-ray Binary 64

0127720501 V4743 Sgr Nova 55

0202760301 Cyg X-1 High Mass X-ray Binary 55

0111360101 Cyg X-2 Low Mass X-ray Binary 50

0136140301 XTE J1650-500 Low Mass X-ray Binary 50

0303280101 Cyg X-2 Low Mass X-ray Binary 43

0411082701 Mkn 421 BL Lac - type object 39

0561180501 Cyg X-2 Low Mass X-ray Binary 38

0610000401 Cyg X-1 High Mass X-ray Binary 31

0551340201 4U 1820-30 Low Mass X-ray Binary 29

0411080301 Mkn 421 BL Lac - type object 26

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