HETG

Follow-on Science Instrument

Contract NAS8-01129

 

Monthly Status Report No. 004

June 2002

 

HETG Science Theme: Active Galactic Nuclei and Jets

 

Prepared in accordance with DR 972MA-002

DPD #972

 

Prepared for

National Aeronautics and Space Administration

Marshall Space Flight Center, Alabama 35812

 

Center for Space Research; Massachusetts Institute of Technology; Cambridge, MA 02139

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1.0 Distribution List for Monthly Status Report

 

 

MIT-External Electronic:

FD03/Mike Smith, MSFC                   Carl.M.Smith@msfc.nasa.gov

PS41/Steve Morris, MSFC                 Steven.D.Morris@msfc.nasa.gov

ES84/Martin Weisskopf, MSFC            martin@smoker.msfc.nasa.gov

 

MIT-External Hardcopy:

                                    None specified.

 

 

            MIT-Internal Electronic:

                                                Deborah Gage             dgage@space.mit.edu

                                                Gail Monahan              gmonahan@mit.edu

 

MIT-Internal Hardcopy:

                                                Claude Canizares         Room 37-582G (via Gail Monahan)

 

 

 

 

 

 

 

 

 

Please send distribution requests and other comments on this document to dd@mit.edu .

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2.0 Schedule of Past and Future Events Relevant to HETG

 

 

Date	Past Events	Comment
June 2-6	AAS meeting, Albuquerque
June 18-20	Chandra Peer Review	2 GTO proposals competing
June 25,26	Chandra Users Committee

 

 

 

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3.0 Instrument Status and Science Support

 

 

3.1 Flight Events and HETG Instrument Status

 

The HETG continues to function with no outstanding issues.

 

There were 7 targets observed in 10 observation intervals by the HETG in June 2002. None of these were in the HETG GTO program.

 

Three of the observations were taken for HETGS calibration purposes: the continuum source 3C 273 was observed at 3 SIM-Z offsets and will allow verification/calibration of the ACIS gain and QE with position. CXC cal group member Herman Marshall is doing the analysis.

 

3.2 Science Support to CXC, SWG, etc.

 

Discussed HETG spatial-spectral analysis techniques and s/w with CXC ISIS scientists for possible future s/w development.

 

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4.0 GTO Science Program

4.1 Observations and Data status

Progress in the GTO program observations and data analyses are noted in the Table of Appendix A. Late breaking news (7/9): the two “competed” HETG GTO targets were highly rated by the peer review in June and will be part of Cycle 4 observations.

 

4.2 Science theme progress

The HETG GTO science efforts span a range of “science themes” given in the list below. This month progress and plans in the “Active Galactic Nuclei and Jets” theme are presented.

 

GTO Science Theme	Abbreviation (for App’ix A)	Researchers (HETG in caps)	Date of last [next] reporting
Stars	Star(s)	dph,nss	Not yet reported
X-ray Binaries & Accretion Disks	XRB	MJ-G,AJ,nss	Not yet reported
Supernova Remnants	SNR	KAF,DD,JMM, AF,jh,gea,tp	May, 2002.
Isolated Neutron Stars	iNS	MDS,hlm	Not yet reported
Galaxies & Clusters of Galaxies	Gal., Clust.	TJ,mw,jh	Not yet reported [Aug.’02]
Active Galactic Nuclei and Jets	AGN, Jet	JL,TF,RG,hlm, pmo	June, 2002.
ISM Absorption	ISM	AJ,nss	Not yet reported
IGM Absorption	IGM	TF	Not yet reported [July’02]

 

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Active Galactic Nuclei and Jets Progress

 

Introduction

In the center (“nucleus”) of many galaxies is a massive black hole, with a mass of one million to one billion times the mass of the Sun. The strong gravitational field of this black hole attracting surrounding gas and stars leads to complex energetic structures around the black hole: torus, disk, and jets. These hot structures can be seen in the radio, optical and x-ray bands. There are many categories of observed AGN depending on the mass of the black hole, the environment around it, and also the orientation that we view it from. The same fundamental process may be behind all of these different-appearing objects.

 

Introductory material on AGN and the figures above are available starting at: http://imagine.gsfc.nasa.gov/docs/science/know_l1/active_galaxies.html

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Summary of AGN GTO Observations

There were several types of Active Galactic Nuclei (AGN) observed with the GTO time. One source is a BL Lac type object (PKS 2155-304), several are radio loud AGN (M 87, NGC 1275, PKS 2149-306, Q0836+7104, 3C 279), many are normal Seyfert (Sy) 1 galaxies (MCG-6-30-15, NGC 4151, NGC 7469, 1H1821+643, Mrk 766, 1ES1028+511) and the remainder are low luminosity Sy 2 galaxies, whose nuclei are obscured (NGC 1068, NGC 5506, IRAS18325-5926). The scientific objectives varied with the source type.

 

 

BL Lac Objects

The BL Lac object PKS 2155-304 was observed in order to verify and analyze absorption features against the bright continuum spectrum. Canizares & Kruper (1984) discovered a deep absorption feature in the spectrum of this source in an Einstein Objective Grating Spectrometer observation. It was interpreted as blue-shifted absorption from ionized oxygen in a jet along the line of sight. The HETGS observations were proposed in order to resolve this feature better to perhaps determine the velocity structure of the jet. The actual spectra have not shown the expected absorption though Marshall (2000, in proceedings of a symposium on Astrophysical Phenomena Revealed by Space VLBI see figure) showed that the spectrum of PKS 2155-304 and another BL Lac object, Mrk 421, were well fit by power law models without significant broad absorption features. Later detailed study revealed a narrow absorption feature that can be attributed to material between us and the BL Lac (Fang et al. 2002, Ap. J. Letters, 572, L127).

 

The spectrum of PKS 2155-304, at left, is colloquially described as “a boring power law”: the clean straight spectra are a tribute to instrument calibration but contain little high-resolution spectral information.

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Radio Loud Quasars

These sources were observed for three reasons. First, two of the targets reside in the deep potentials of large galaxy clusters (M 87 in the Virgo cluster and NGC 1275 in the Perseus cluster) so there was the expectation of observing the cooling gas in emission from an extended region and in absorption against the AGN point source continuum. Four of these sources have extended radio emission and jets that were expected to be detectable. Finally, the bright sources were good "lamps" for observing absorption from intervening material in the intergalactic medium (IGM).

 

The observation of NGC 1275 showed the core X-ray nicely but the spectrum was disappointing, being simply a pure power law and it was not strong enough to provide good absorption lines. Marshall (2000) mentioned the HETGS results on NGC 1275 but there is no other report yet. The imaging data were superseded by direct ACIS observations, published by Fabian et al. (2000, MNRAS, 318, 65) with one member of the HETGS team (P. Ogle). The spectra of two of the radio loud AGN were published in an IGM study (PKS 2149-306 and Q0836+71) but were otherwise unremarkable.

 

The zeroth order data for M 87 showed significant detail in the X-ray jet (Marshall et al. ApJ, 564, L683). There was a good match between features in the radio and optical images (see Figure on next page) so that the spectral energy distributions (SEDs) over the radio—optical—X-ray range could be measured for many of the knots. These SEDs showed significant evolution along the jet in the sense that the X-ray flux drops relative to the optical flux systematically along the jet. The interpretation of this effect in terms of jet models is not yet understood.

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The jet in M 87 is shown, top to bottom, in i) Radio, ii) Optical (HST), iii) X-Ray (Chandra) images.

In the final panel iv) the X-ray image is overlaid with contours from the optical smoothed to Chandra resolution.

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Normal Seyfert 1 Galaxies and Quasars

Some of the more luminous AGN seem to have rather featureless spectra even if not radio loud, such as 1H1821+643 and 1ES1028+511. Both targets were observed in order to find absorption features in the intervening IGM (more on this in a future report). Fang et al. (2002, ApJ, 565, 86) showed that the spectrum had a strong neutral Fe K line and a weak Fe XXVI line which are thought to arise in the atmosphere of an accretion disk. The spectrum of 1ES1028+511 has not yet been analyzed.

 

MCG--6-30-15 has provided a bounty of spectral features in its HETGS spectrum that can be attributed to warm gas along the line of sight within the host galaxy. Lee et al. (2001, ApJ, 554, L13) presented the 0.5-1.0 keV portion of the spectrum to show that it is rich with absorption lines from a moderately ionized plasma (see figure next page). An absorption edge is observed near 0.7 keV (in the rest frame) while the O VII edge was expected near 0.74 keV. The shift is thought to result from significant absorption by neutral Fe. In addition to the absorption lines, MCG-6-30-15 has a strong Fe K line that is broad and a weaker slightly broadened component. Lee et al. (2002, ApJ, 570, L47) showed that the broad line was similar to that found in previous ASCA observations but that the lack of a strong narrow line indicated that there was little reflection off of a molecular torus, often invoked to explain the differences between Sy 1 and Sy 2 galaxies.

 

The 0.5-1.0 keV portion of the spectrum of MCG—6-30-15 shows spectral features that can be attributed to warm gas (moderately ionized plasma) along the line of sight within the host galaxy (Lee et al. 2001, ApJ, 554, L13.) An absorption edge is observed near 0.7 keV (in the rest frame) while the O VII edge was expected near 0.74 keV. The shift is thought to result from significant absorption by neutral Fe.

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NGC 4151 shows extended emission in both the X-ray and optical images, shown at left. This extended gas follows the structure of the narrow line region (NLR), indicating that the X-ray and NLR gas are co-spatial. When observed with the HETGS, it was thought that the spectrum would be representative of normal Sy 1 but the continuum was very weak, so the soft portion of the spectrum was dominated by emission lines, figure below. Obscuration of the hard power law component by neutral material with a very large optical depth is more typical of Sy 2 galaxies (next section). The unusual weakness of the hard X-ray continuum allowed Ogle et al. (2000, ApJ, 545, L51) to measure the emission lines from extended gas that is photo-ionized by the hard, but obscured, continuum. Comparing the O VIII line (seen below at 19A) and Fe K line (not shown) indicates that the width of the Fe K line is probably dominated by the spatial size of the galaxy, instead of by Doppler motions.

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Seyfert 2 Galaxies

Several early observations of Sy 2 galaxies showed significant emission lines in the soft X-ray portion of the spectrum. The results from NGC 1068 (Ogle et al., 2002, ApJ, submitted) were no exception, being rich with lines from a variety of ions as well as showing recombination features indicative of photo-excitation (see figure above). The line-emitting gas for ‘1068 is spatially extended as in the case of NGC 4151 discussed previously.

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AGN and Jets Plans and Further Work

 

 

* We have spectra in hand for two more Sy 2 galaxies that can be analyzed in a manner similar to that of NGC 1068: NGC 5506 and IRAS18325-5926. A preliminary look shows that the line spectra of these two are not quite as rich for reasons that are not yet understood.

 

* A more full analysis of the absorption line spectrum of MCG-6-30-15 is nearing completion and a similar analysis is nearly complete for Mrk 766, which has a spectrum that is comparable to MCG-6-30-15 in terms of absorption features.

 

* There have been and will be several more observations of continuum sources that will be analyzed primarily for absorption features due to the IGM (to be described in a subsequent report) In addition these spectra will be analyzed for other AGN features.

 

* The quasar MRC 2251-178 will be observed this Fall and should also show absorption lines due to a warm absorber.

 

* The Sy 1 galaxy NGC 7469 will be observed in October 2002 jointly with HST so an analysis of those data will require examining the detailed absorption spectra in the optical band for matches with the X-ray absorption features.

 

* In addition to the spectra, the images of these AGN can show X-ray emission coincident with radio jets. For example, the image of 3C 279 obtained in March shows extended emission aligned with a radio emitting jet, so a separate paper will be written about this X-ray jet.

 

 

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4.3 HETG-related Software: Development, Evaluation, and Support

 

A variety of software has been created or modified in-house for use in analyzing AGN and jet observations. Most of the effort has gone into developing custom IDL + ISIS programs to systematically analyze narrow absorption and/or emission features presented in the AGNs' spectra. The basic idea is to: (1) obtain an accurate measurement of the continuum; (2) find narrow features above a certain signal-to-noise ratio; (3) fit the line/dip using ISIS; (and 4) obtain the line id using available atomic databases.

 

4.4 Presentations (June)

 

M.D. Stage “Recent Results Fitting Chandra Spectra of Thermally Radiating Neutron Stars” AAS Albuquerque, 6/6/02.

 

 

4.5 Publications (June), see also: http://space.mit.edu/csr_pubs.html

 

M.A. Jimenez-Garate, et al., “High-resolution X-ray Spectroscopy of Hercules X-1 with the XMM-Newton RGS: CNO Element Abundance Measurements and Density Diagnostics of a Photo-ionized Plasma”, ApJ accepted 2002, astro-ph/0206181.

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5.0 Systems and Engineering Support

 

5.1 Documentation and “Design Knowledge Capture”

 

No activity this period.

 

5.2 Spares Retest and Test Instrumentation

 

Returned vacuum gauge is installed and operational; debugging system control s/w and h/w .

 

5.3 Anomalies, Insert/retract, etc. Support

 

No actions this month.

 

6.0 Management

6.1 Program Office & NASA Support

 

We’re standing by to support finalization of the GFE equipment list as needed.

 

6.2 MIT-internal management activities

 

Planning of rooms and computers for new arrivals this fall is completed. Order for 2 new computers has been placed.

 

7.0 Open Issues, Problems, etc.

 

There are no known critical open issues or problems regarding the HETG. Thanks to MSFC for speedy approvals of computer purchases and Prof. Canizares’ travel.

 

Appendix A. GTO Observation Status Tables

 

Notes:

1.    Entries indicating progress during this period are shown in this font.

2.    For CSR Publication references (CSR-YY-NN) see http://space.mit.edu/csr_pubs.html

3.    Up-to-date observation information can be obtained from http://cxc.harvard.edu/cda/ using the WebChaSeR link.

 

Cycle 4 (to be finalized after Peer Review in June)

Object Science Theme	AO	Obs ID	Seq. No.	Expos. (ks)	Observer / Analyst	Start Date	Comments & Analysis	Talks and Publications
4U 1626-67 XRB	4	---	---	[100.0]	N. Schulz		Prop. No.: 04400027
Sco X-1 XRB	4	---	---	[15.0]	N. Schulz		Prop. No.: 04400046
H1426+428 IGM	4	---	---	[102.0]	T. Fang		Prop. No.: 04700987
Mrk 290 AGN	4	---	---	[250.0]	J. Lee		Prop. No.: 04700988
TV Crit Stars	4	---	---	[100.0]	D. Huenemoerder		Prop. No.: 04200007, Selected in peer review!
E0102 SNR	4	---	---	[140.0]	K. Flanagan, D.Dewey		Prop. No.: 04500008, Selected in peer review!

 

Cycle 3

Object Science Theme	AO	Obs ID	Seq. No.	Expos. (ks)	Observer / Analyst	Start Date	Comments & Analysis	Talks and Publications
MRC 2251-178 AGN	3	2977	700416	[150.0]	J. Lee/ H. Marshall	---	Scheduled: Sept. ‘02
NGC 7469 AGN	3	3147 (+2956)	700586	[70.0] [+80.0]	J. Lee/ H. Marshall	---	Scheduled: Oct. ‘02 w/HST Supplement Kriss GO.
1H 0414+009 IGM	3	2969	700408	[93.0]	T. Fang	---	Scheduled: Aug. ‘02
GX 349+2 XRB	3	3354	900193	35.2	N. Schulz, A. Juett	4/9/02	For ISM study; Observed on 4/9; data available 5/2 [4/02]
NGC 2362   Stars	3	2525, 2526	200133, 200134	44.5, 43.8	N. Schulz, P. Wojdowski, J. Kastner/RIT	3/28/02, 4/23/02	Analysis continues. Previewed the data.[5/02] Observed 4/23 [4/02]
1ES 1028+511 IGM, AGN	3	2970, 3472	700409	21.8, 69.6	T. Fang	3/27/02, 3/28/02	Both data sets are in-house [4/02]
3C 279   AGN, Jet, IGM	3	2971	700410	108.2	T. Fang, H. Marshall	3/21/02	Data reduced; jet seen in zo image.[5/02] Data are in-house [3/02].
IRAS 18325-5926 AGN	3	3148, 3452	700587	56.9, 51.1	J. Lee	3/19/02, 3/23/02	Data are in-house [3/02].

 

Cycle 2

Object	AO	Obs ID	Seq. No.	Expos. (ks)	Observer / Analyst	Start Date	Comments & Analysis	Talks and Publications
Cyg X-2 XRB	2	1016	400094	15.1	N. Schulz, A. Juett	8/12/01	ISM study: cold absorption edges[5/02]
Cas A SNR	2	1046	500112	69.9	K. Flanagan, D.Dewey	5/25/01	Si knot analysis started [3/02].	In CRC Royal society talk 2002.
4U 0142+61   iNS	2	1018	400096	25.4	N. Schulz, A. Juett	5/23/01	Finishing additional analysis [3/02]	ApJ, 2002, 568, pp. L31, HEAD-2002[4/02] CSR-02-16[3/02]
Mrk 766 AGN	2	1597	700213	90.5	P. Ogle, J. Lee	5/7/01	Paper in preparation [4/02]
NGC 4696 Gal.	2	1560	600117	85.8	M. Wise	4/18/01	To be analyzed.
EXO 0748-676   XRB	2	1017	400095	49.0	N. Schulz, H. Marshall, M. Jimenez-Garate	4/14/01	Analyzed burst spectra; Created spectral lightcurves[5/02]	HEAD02
SS 433 XRB, Jet	2 2 1	1019, 1020, 106	400097, 400098, 400019	23.7, 23.0, 28.9	H. Marshall, N. Schulz	3/16/01, 11/28/00, 9/23/99	Complete analysis of Cycle 2 data	CSR-02-01, CSR-01-78
1H 1821+643 AGN, IGM	2	1599	700215	101.3	P. Ogle, T. Fang	2/9/01		CSR-02-16.5[4/02], CSR-01-69
Iota Orionis Stars	2	599, 2420	200075	37.6, 12.9	N. Schulz, P. Wojdowski	2/7/01, 2/8/01	Data reviewed[5/02]
TY Pyx (HD77137) Star	2	601	200076	49.8	D. Huenemoerder	1/3/01	Preliminary analysis done.	(spectrum in CSR-02-02)
N103B   SNR	2	1045, 2410, 2416	500111	74.0, 25.7, 17.6	K. Flanagan, J. Migliazzo, D. Dewey	1/1/01, 1/3/01, 1/2/01	NEI, vshock, and Si 2-D analyses.[4/02] 1-D and 2-D analyses started [3/02]	Poster: HEAD-2002[4/02]
NGC 5506 AGN	2	1598	700214	90.0	P. Ogle, J. Lee	12/31/00		Paper in preparation[4/02]
ZW 3146 Clust.	2	1651	800119	167.8	M. Wise	12/25/00	Re-analysis continued w/ ISIS; started[5/02]	Cluster paper in draft[5/02]

Cycle 2, above.

 

 

 

Cycle 1

Object	AO	Obs ID	Seq. No.	Expos. (ks)	Observer / Analyst	Start Date	Comments & Analysis	Talks and Publications
NGC 1068 AGN	1	332	700004	46.3	H. Marshall, P. Ogle, J. Lee	12/4/00	Examine zeroth-order pileup[5/02]	Paper in submitted[5/02]
4U 1626-67 XRB	1	104	400017	40.0	N. Schulz	9/16/00		CSR-01-81
AR Lac   Star	1	6,7,8, 9,10,11	20000N: 4,5,6,7,8,9	32.5,7.5, 7.5,32.6, 7.3,7.3	D. Huenemoerder	9/11/00- 9/19/00	Analysis complete.	Co-authors comments added; Internal draft circulated.[4/02] CSR-01-112
Abell 1835 Clust.	1	49896 511	800019	9.8 127.0	M. Wise	8/25/00 8/26/00	Re-analysis continued w/ ISIS; started[5/02]	Cluster paper in draft[5/02]
N132D   SNR	1	121, 1828	500008	22.3 77.6	K. Flanagan, D. Dewey	7/19/00 7/20/00	Fe and O line ratios from many regions/features	CSR-01-10,26, Y2Chandra01
TW Hydra Star	1	5	200003	48.3	D. Huenemoerder, J. Kastner	7/18/00	Analysis complete.	CSR-02-02, CSR-01-29
NGC 4486, M 87 Gal., AGN, Jet	1	241	600001	38.5	M. Wise	7/17/00	Examination begun.
GX 301-2 XRB	1	103	400016	40.0	N. Schulz	6/19/00	Re-analysis initiated [3/02]	Draft paper begun [3/02], AAS00
NGC 1399   Gal.	1	49898, 240, 2389	600214 600000	13.2 44.1 14.8	M. Wise	5/8/01 6/15/00 5/8/01	Examination begun.
Vela X-1 XRB	1	102	400015	28.4	N. Schulz	4/13/00		ApJ, 2002, 564, L21
MCG –6-30-15 (w/Fabian) AGN	1	433	700105	128.2	H. Marshall, J. Lee	4/5/00		Lee et al 2002, CSR-02-15 [3/02], CSR-01-02
NGC 4151 AGN	1	335	700007	48.0	H. Marshall, P. Ogle	3/5/00		CSR-00-87
PSR B0656+14 iNS	1	130	500017	38.1	H. Marshall	11/28/99	LETG/HRC	Paper accepted, CSR-02-12[3/02]
PKS 2149-306 IGM, AGN	1	336, 1481	700008	36.0 54.8	H. Marshall	11/18/99 11/20/99		CSR-01-67
Trapezium   Stars	1	3, 4	200001 200002	50.1 31.3	N. Schulz, D. Huenemoerder	10/31/99 11/24/99	Draft paper started. Detailed modeling work continued[5/02]	CSR-01-118, CSR-00-89, CSR-00-75
4U 1636-53 XRB	1	105	400018	29.8	N. Schulz	10/20/99		AAS00
PKS 2155-304   AGN	1	337, 1703, 1705	700009 700261 700263	39.1 26.2 25.8	H. Marshall, T. Fang, J. Lee	10/20/99 5/31/00 5/31/00	HETG and LETG w/ACIS-S	ApJ Letter in press. Paper accepted.[4/02]
Cyg X-1   XRB	1	107, 1511	400020	2.5 12.6	N. Schulz, H. Marshall, J. Miller	10/19/99 1/12/00	Second paper continuing[5,6/02] Paper in process [3/02]	ApJ, 2002, 564, pp. 941 (CSR-01-57), HEAD00
II Peg (HD 224085) Star	1	1451	200010	43.3	D. Huenemoerder	10/17/99	Analysis complete.	CSR-01-50
Q0836+7104 IGM, AGN	1	1450, 1802	700006	61.0 14.1	H. Marshall	10/17/99 8/25/00		CSR-01-67
PKS 0745-191 Clust.	1	510, 1509, 1509	800018	45.3, 40.4, 39.9	M. Wise	10/14/99 4/25/00 3/4/00	Re-analysis continued w/ ISIS; started[5/02]	Responded to referee report. ApJ submitted, Hicks et al. [3/02]
PSR B0833-45 iNS	1	131	500018	36.1	H. Marshall	10/12/99		HEAD00
NGC 1275 AGN	1	333, 428	700005 700201	53.2 25.0	H. Marshall, P. Ogle	10/10/99 8/25/00	Determined PL spectral slope	No pubs of note
E0102   SNR	1	120, 968	500007	88.2, 49.0	K. Flanagan, J. Houck, A. Fredricks, D.Dewey	9/28/99 10/8/99	“One-ion” fitting and masses. Fluxes and ratios in “arc”. Initial calc O mass.[4/02]	Final polishing of ApJ paper [3-6/02], CSR-01-10,11,24,25,26, Y2Chandra01
Object	AO	Obs ID	Seq. No.	Expos. (ks)	Observer / Analyst	Start Date	Comments & Analysis	Talks and Publications

Cycle 1, end.