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Curriculum Vitae
PERSONAL:
Name : Tapasi Ghosh
Contact Address : Arecibo Observatory, NAIC,
HC3 Box 53995, Arecibo, Puerto Rico,
PR 00612. USA,
Tel: (787)­878­2612, Fax: (787)­878­1861, E­mail: tghosh@naic.edu
Date and Place of Birth : 13 November 1959, Calcutta, India.
Nationality : Indian
Marital Status : Married, with an ten year old daughter.
Fluency in Languages other than English: My mother tongue is Bengali
(one of the 18 o#cial languages in India), although I have been using English for
more than 25 years and most of my formal education was in English. In addition,
I have a limited command of Spanish, as well as a brief exposure to Dutch.
EDUCATION:
B.Sc. Physics (Hons) Lady Brabourne College, Calcutta, India. 1979
M.Sc. Physics University College of Science, Calcutta, India. 1981
Post M.Sc Associate Saha Inst. of Nuclear Phys., Calcutta, India. 1982­83
(Bio­Physics)
Ph.D (Astronomy) Indian Inst. of Science, Bangalore, India. 1990
Thesis Topic: ``Low­Frequency Variability of
Compact Extragalactic Radio Sources''
EMPLOYMENT:
. Dec 1990 -- Nov 1992: Post­doctoral Fellow, Netherlands Foundation for
Research in Astronomy, Dwingeloo, The Netherlands.
. Dec 1992 -- Present: Research Associate with NAIC, at the Arecibo Obser­
vatory. Present responsibilities include coordinating all Very Long Base­
line Interferometry (VLBI) related work and performing the absentee VLBI
observations and the relevant system calibrations. I also provide general
visiting observer support, and am responsible for calibration and documen­
tation of the S­band receivers on the 305­m telescope. I annually supervise

``Research Experience for Undergraduate (REU)'' summer students and
carry on a personal astronomical research programme.
CURRENT RESEARCH INTERESTS:
I. Atomic and molecular gas in AGN host :
The host galaxies of AGNs are di#cult to detect at most wavelengths as the line
and continuum radiation from the associated active nuclei swamps the emission
from the underlying galaxy. Despite this di#culty, optical ``fuzz'' showing stel­
lar spectra has been detected around nearby quasars using both ground­based
telescopes and the HST. In addition, near­infrared imaging has been quite suc­
cessful in detecting the host galaxies of Seyferts and nearby quasars. Recently,
these types of search have been extended to a redshift of z = 2.3. The picture
that is emerging suggests that at higher redshifts, radio­loud QSOs are hosted by
exceptionally luminous galaxies, while the majority of QSO hosts are too faint
to detect.
At radio wavelengths, searches for neutral hydrogen and molecular lines in QSO
spectra have been made since the first detection of HI absorption towards 3C286
by Brown & Roberts in 1973. As quasar nuclei emit neither #21­cm HI line
radiation, nor molecular lines, their host galaxies can generally be observed as
easily in these transitions as if they contained no active nuclei at all. HI emission
has been detected in QSOs with redshifts up to z = 0.1, while at higher redshifts
little work has been done. HI absorption associated with a host galaxy has been
detected only for the BL Lac object, PKS 1413+135 at z=0.246, while molecular
gas and dust emission has recently been detected in a number of active galaxies
with redshifts up to 4.7.
In collaboration with various Radio Astronomers around the globe, I am carrying
out the following projects in this area:
1. CSS/GPS Sources:
Collaborators: Drs C.J. Salter(NAIC/AO), D.J. Saikia (NCRA, India), Jeyaku­
mar and Stutzki (U Cologne, Germany)
Observations for an Arecibo and GMRT study/search HI absorption and OH
emission/absorption in Compact Steep Spectrum (CSS) and GigaHertz Peaked
Spectrum (GPS) radio sources was completed in March 2004. This has made use
of the Double Position Switching technique developed by ourselves over recent
years. The results include a first detection of deep HI absorption within the
CSS galaxy, 3C258 (z = 0.165), and confirmation of a number of HI absorption
detections by other telescopes, usually with better signal­to­noise. Upper limits
are also placed on OH spectral lines for the sample. A global VLBI proposal to
image the HI absorption in 3C258 is awaiting scheduling.

2. ARP 220:
As a ``Hands­On Experiment'' for 4 students at the 2nd NAIC/NRAO School
on ``Single­Dish Radio Astronomy'', held in Green Bank in Aug 2003, C. Salter
and I supervised observations of HI and all 4 OH lines in the prototype starburst
galaxy, Arp 220. The aim of the experiment was to illustrate the problems of
baseline ripple due to standing waves when the source observed has significant
continuum emission, and how this can be corrected by Double Position Switching.
This end was well achieved by the students, but we had an added surprise in that
the profiles measured for both satellite lines of OH were completely di#erent to
the previously published profiles of Baan and Haschick (1987). Our profiles
contain velocity ranges where both emission and absorption are present. We
believe that Baan & Haschick probably removed the absorption components in
the spectra via their baseline fitting. The new profiles are now being written
up for publication, including the four summer students among the authors. To
interpret these complex OH satellite line profiles, we have recently acquired global
VLBI data to image both of the satellite lines at milliarcsecond resolution.
3. PKS 1413+113:
Collaborators: Nissim Kanekar (NRAO, USA), Jayaram Chengalur (GMRT,
Inida)
We have detected the two 18cm OH satellite lines from the z # 0.247 source
PKS1413+135; the 1720 MHz line in emission and the 1612 MHz line in ab­
sorption. The 1720 MHz luminosity is LOH # 354L# , more than an order of
magnitude larger than that of any other known 1720 MHz maser. The profiles
of the two satellite lines are conjugate, implying that they arise in the same gas.
This allows us to test for any changes in the values of fundamental constants,
without being a#ected by systematic uncertainties arising from relative motions
between the gas clouds in which the di#erent lines arise. Our data constrain
changes in G # g p [# 2 /y] 1.849 , where y # m e /m p , and are consistent with the dif­
ferent constants remaining unchanged from z # 0.247 to today. If g p and m e /m p
are assumed to not vary, we obtain ##/# = 0.6 ± 1.0 â 10 -5 over the range
0 < z < 0.247.
4. Search for Water Vapour Masers in High­redshift AGNs:
Collaborators: Smita Mathur (Ohio State Univ, USA), and C. J. Salter(NAIC/AO)
Strong 22­GHz water­vapor masers have so far been detected in about 20 nearby
AGNs. These ``megamaser'' sources are mostly associated with Seyfert 2 and
LINER galaxies whose active nuclei are hidden by a large column density of
optically obscuring, X­ray absorbing gas. Detailed studies of H 2 O masers with
VLBI imaging and spectral monitoring have become important tools for probing
dense gas near the central engines of these sources, investigating the properties

of their accretion disks and measuring the masses of their (supermassive) black
holes. Such studies have also been employed to estimate geometrical distances
completely independent of the rungs of the extragalactic distance ladder.
However, so far most of the detections of extragalactic H 2 O masers have been
in relatively nearby objects (with systemic velocities less than 7500 km/s), and
(hence) in low­luminosity AGNs. To date, two searches of high­z water masers
have been initiated using the 100­m E#elsberg telescope and the VLBA using
the U, X, C and L­band receivers at those telescopes. Their observations are
sensitive to flux densities of 20 and 40 -- 50 mJy respectively. No detection has
yet been reported. We notice that one of the selection criteria for these studies
has been detectable X­ray flux in their targets. X­ray emission is an ubiquitous
property of quasars, and indeed, according to models of X­rays are responsible
for keeping the molecular gas ``warm'' enough for maser production. However,
direct exposure to X­rays tend to make the gas too hot to form molecules, and the
necessary condition for making the environment conducive for maser production
appears to be substantial shielding from the X­ray source. Indeed all the nearby
maser sources, observed in X­rays, show large absorption in soft X­rays Thus,
the appropriate selection criterion appears to be ``soft X­ray absorption'' instead
of ``detectable X­ray flux'' which may, in fact, select against obscured sources.
Hence, we have undertaken a H 2 O­maser search in the redshift ranges 1.22 -- 1.78
and 2.70 -- 4.55 using the X and C­band receivers of the 305­m telescope in 35
AGNs either with soft­X­ray absorption or other indirect evidence of obscuring
torus such as compact steep spectrum double radio structures.
Two sessions of observations have already been carried out in September and
November 03 (A1785) covering about 25 % of our sample. During this time,
the characteristics of the X­band receiver has improved by about 60 %. We are
looking forward to completing this project in the near future.
II. Damped Lyman­# Absorbers:
Much of what is known about neutral gas at high redshifts comes from the
study of Lyman­# absorption lines observed in the spectra of distant quasars.
The highest HI column density systems, the so­called damped Lyman­# (DLA)
systems, are of particular interest, because they are believed to be the precursors
of z = 0 galaxies.
The typical mass of DLA systems is currently controversial. Small sizes are pre­
ferred in hierarchical structure formation theories, while a popular model in the
observational literature assumes that DLAs are large, massive disks. Further,
from local 21­cm emission line studies, it is expected that the absorption cross
section is dominated by the disks of spiral galaxies. On the other hand, galax­
ies associated with DLAs appear to cover all morphological types, and are not
confined to spirals alone. At present, I am involved in two projects in this area:

1. Unbiased search for Damped Lyman­alpha Absorbers at radio wavelengths:
With Drs. C.J. Salter (NAIC/AO), and K. O'Neil (NRAO), I am searching for
low­redshift Damped Lyman­alpha (DLA) systems via 21­cm absorption along
the lines­of­sight to 200 compact distant radio sources. This will help improve
both DLA statistics for 0 < z < 0.3, and knowledge of the HI mass fraction
at z # 0 . The detection level for these low redshift systems will enhance the
studies of cosmological evolution of the nature and number density of DLAs, and
their interstellar media. In addition, as the source sample is radio selected, dust
obscuration will not bias the statistics.
An initial epoch of this observation took place in Nov 03, and Feb 04. We have
successfully used the Wideband Arecibo Pulsar Processor (WAPP) to acquire
400­MHz spectra, its first use in this mode and have developed an IDL­based
analysis pathway. A regorous RFI­detection/flagging/excision method is also
being developed to identify real signature of DLA systems in these spectra. The
observations have already detected two DLA lines in a test run, both already
known, but demonstrating the robustness of the approach.
HI in High­z DLAs:
Collaborators: Nissim Kanekar (NRAO, USA), Jayaram Chengalur (GMRT,
Inida)
Using the low­frequency capability of Arecibo 305­m telescope, we are searching
for HI absorption in a high redshift (z # 3.38) Damped Lyman­# absorber
(DLA) toward PKS 0201+113, and two other candidate DLAs at z # 2.4 seen
toward two radio loud quasars. Our observations are sensitive to 10 4 K gas in
the z = 3.38 absorber providing the first possibility of detecting warm neutral
medium at high redshifts. For the two z # 2.4 DLAs, the observations, when
completed will be sensitive to spin temperatures of # 1000 K, a value typical
of that in most damped systems. The observations will test an emerging trend
that high­z DLAs predominantly contain the warm phase of HI, while both cold
and warm HI are seen in low­z systems. The search also include OH absorption
in two lower redshift absorbers at z # 0.24 using the L­wide receiver to study
chemical evolution of DLAs.
III. VLBI survey of faint FIRST sources:
With Drs. R. Porcas, W. Alef (MPIfR, Bonn) & C. Salter (NAIC), I am con­
ducting a VLBI visibility survey of around 1000 faint (down to 1.4­GHz flux
density of 1 mJy) sources selected from the VLA­FIRST survey. This will make
use of the ultra­high sensitivity achievable with the Arecibo and E#elsberg tele­
scopes at 21 cm using VLBA4/MK4 recording. The selected sources lie within
the area of the Sloan Digital Sky Survey, and it is expected that 50be identified
with SDSS objects down to m(V) 24 mag. Thus redshifts of many objects in

the sample should eventually become available. Amongst other uses, our survey
will help identify the fraction of AGNs (as opposed to starburst galaxies) in the
faint source population, and the number of faint targets existing for such future
instruments as the high­resolution options for the SKA.
IV. North Ppolar Spur:
With Chris Salter (NAIC/AO), the first wide­area continuum imaging with the
upgraded Arecibo telescope was made in 2000. This mapped an area of 6 deg x
6 deg at 430 MHz within the North Polar Spur (Loop I), where a semi­circular
emission arc is superposed on the larger feature. This arc may represent the rem­
nant of a second­generation supernova resulting from star formation within the
compressed shell of Loop I, and is a promising candidate for the ``reheating event''
often invoked to explain the X­ray emission of Loop I. It is hoped that these high­
resolution total­power observations will aid understanding of the nature of the
arc, and its relation to Loop I. Analysis of the data proved to be complicated
due to the lack of many header parameters in the data format available at the
epoch of observation. However, the reduction of the images was undertaken in
the summer of 2003, in conjunction with REU student, Kit Reilly. Consider­
able progress had been made when Kit was killed in a tragic hiking accident. Dr
Salter and I returned to the data later in the year, and produced a first map of
the region which were presented at the Atlanta AAS meeting. It now remains to
optimise these maps and to basket­weave the orthogonal coverages to produce a
final image.
V. Continuum Surveys with ALFA:
With a number of members of the GALFA Continuum science subconsortium,
Taylor (Calgary), Deshpande, Salter and Freire, a pilot survey towards a GALFA
Continuum Survey is being made. This uses the L­wide receiver, and is exploring
the e#ectiveness of the meridian NODding observing technique proposed for the
full GALFA Continuum Transit Survey (GALFACTS). Two fields will eventually
be mapped with Nyquist sampling. The data analysis pipeline is being developed
for this study which will serve as the proptype for the full GALFACTS survey.
SERVICE WORK AT ARECIBO OBSRVATORY:
. VLBI related work:
-- I am a member of the Arecibo VLBI group, and have been actively
involved in co­observing with the VSOP space antenna, HALCA, us­
ing a Canadian S2 recorder system. From the return to service of
the upgraded telescope in mid 1997 until NASA tracking support for
HALCA ceased recently, there have been 43 Arecibo VLBI observing
runs. Jointly with Chris Salter, I have conducted all these observa­
tions including subsequent calibration, system checks and tape han­

dling. We had no failure to detect fringes that can be attributed to
problems at Arecibo.
-- In late 1996, Chris Salter and I prepared a proposal to the NSF Ma­
jor Research Instrumentation (MRI) Program for the purchase of a
broad­band VLBA­4 recorder and associated hardware for Arecibo.
We heard in September 1997 that the proposal had been success­
ful, and was to be fully funded (about US $ 500,000.00). The unit
arrived at AO in March 2001. Since then, I have been involved in
testing/commissioning the recorder (along with three other members
of the VLBI group). Since 2001 my main service role at Arecibo ob­
servatory has been to act as the ``Friend of VLBI''.
With hardware and software support from Dr. John Hagen and
Je# Hagen at Arecibo, Chris Salter, Emmanuel Momjian and I
have been carrying out VLBA­4 runs, co­observing with both the
European VLBI Network and the VLBA of NRAO, USA. (see,
http://www.naic.edu/#astro/aovlbi)
-- In Apr 2004, the observatory acquired a disk­based Mark­5A record­
ing system enhancing the corcording rate for VLBI observation from a
maximum of 512 Mbits­per­sec to 1024 Mbits­per­sec. We integrated
and tested the system and joined with the EVN in successful e­VLBI
runs (http://www.naic.edu/#astro/aovlbi/press release/eVLBI AR.htm).
Regular use of the disk­recorder will begin soon.
. Spectrum Management and RFI protection related work: Until
April 2001, I was responsible for coordinating the local activities of the
Spectrum Management and RFI­protection Group (SMARG) at Arecibo.
This required working with a 10­member group consisting of engineers,
software personnel, scientific sta# and telescope operators to ensure that
the radio­spectrum allocated to radio astronomy is maintained interference
free and protected at Arecibo. This entailed minimising emissions from
on­site equipment, monitoring the wider radio environment, searching for
sources of interference using a mobile unit, and liaison work with local spec­
trum users and authorities in cases of complaints. Details of the functions
of this group can be found at http://www.naic.edu/#rfiuser/main.html.
. Visiting Observer Support: As well as running VLBI observations, I
have been the friend­of­the­telescope for a number of spectral line projects
since the completion of the Arecibo upgrade seven years ago.
. NAIC/AO Newsletter: Between Mar 1994 -- Feb 2000, and Nov 2001
-- Jul 2004 I have been the co­editor (along with Dr. Jonathan Friedman)
of the AO/NAIC Newsletter. This is published approximately three times
per year. This work has involved me in planning, editing and producing
the Newsletter.

TEACHING­RELATED EXPERIENCE:
Along with Chris Salter, I have supervised the doctoral thesis of Jos’e Francisco
Salgado from the University of Michigan (April 2000).
I have supervised the following undergraduate summer students between 1993
and 2004 (in NSF's REU Program). The name, a#liation and project title of
each student is listed below:
. 2003: Kit Reilly (deceased, New College, Fl.), ``Continuum Mapping of
NPS'', Chris Salter is a co­invetigator in this project.
. 2002: Samantha Stevenson (Weslyan College), ``Evolutionary Tracks of
12­micron sample Seyfert Galaxies'', Leslie Hunt and JoAnn Eder are co­
investigators in this project.
. 2001: SunMi Chung (Weslyan College), `` PKS1004+13: The Rosetta Stone
for BAL Quasars ?'', Chris Salter and Daniel Altschuler are co­investigators
in this project.
. 1999: Dargan Frierson (North Carolina State University) ``HI spectra of
Seyfert Galaxies and testing the Unification Scheme''. Jo Ann Eder and
Chris Salter are co­investigators in this project.
. 1998: Monique Aller (Wellesley) ``A Search for High Redshift Hydrogen
Absorption in Radio­Loud Quasars''. This used both the 430­MHz line
and Gregorian feeds. The data analysis involved the development of var­
ious techniques for RFI excision. Mike Davis and Chris Salter are co­
investigators in this project.
. 1998: Dale Kocevski (Univ. of Michigan) ``The RFI Environment as seen by
the Gregorian L­band Receiver.'' With Jo Ann Eder and I, Dale analysed
drift­scan data taken on a total of 15 nights between November 1997 and
April 1998 and spanning the entire frequency range then covered by the
receiver, 1360 ­ 1685 MHz. The RMS and average per channel over daily
observing periods were calculated, plotted and stored for reference in the
Control Room. Dale also listed the worst o#enders and their occupancy
rates (the fraction of nights during which the RFI was present). This RFI
information has helped many subsequent observers to plan their observing
strategies.
. 1997: Francisco Acevedo (Embry­Riddle College, Florida), ``Measurement
of the Electromagnetic and Radio Frequency Interference (EMI and RFI)
at Key Locations within the Observatory''. This work produced a list of
equipment producing considerable RFI, which were subsequently shielded.

. 1996: Cesar Tavarez (Univ. of Mayaguez, Puerto Rico), ``Analysis of Ra­
dio Frequency Interference Monitoring Data collected round the Clock at
Arecibo Observatory''. The results provide valuable percentage occupancy
plots for the various spectrum users as functions of both frequency and
time of day.
. 1995: Evan Jones (SMSU, USA), ``On the Environmental Triggering of
Radio Emission in Seyfert Galaxies''.
. 1994: Deepa Iyengar (Carleton College, USA), ``VLBI imaging of the
scatter­broadening of compact extragalactic radio sources seen through the
plane of the Galaxy''.
. 1993: Ben Oppenheimer (Columbia Univ, NY), Co­supervised with
Chris Salter on ``Refractive interstellar scintillations of the pulsar, PSR
1933+16''.
Lectured on ``Radio Galaxies and Quasars'', ``Engery Generation Mechanism in
Astronomical sources'', ``AGNs'', and ``Radio Interferometry'' to the AO summer
students between 1993 and 2004.
In addition, I have lectured at the First NAIC/NRAO Single­dish Summer School
at Arecibo Observatory in 2001 and supervised 'hands­on' experiments in both
the First and the Second NAIC/NRAO summer shcools in 2001, and 2003.
SOFTWARE and DATA REDUCTION EXPERIENCE :
Since 1983, I have been using Fortran as my basic programming language. I have
worked with PDP, Alliant, Vax/VMS, Unix, Linux and Solaris operating systems.
I am also familiar with a variety of word processing and desk­top publishing
software (both Windows and Apple­Macintosh based). I am conversant with
html­based web­page developments.
For Astronomical data reductions, I have used the following software packages:
. The OSRT Calibration and Synthesis mapping package (a number of new
programmes were developed by myself in order to facilitate the particular
needs of the Ooty flux­density monitoring programme)
. The Ooty Interplanetary Scintillation (IPS) data reduction package
. The NRAO AIPS image processing system
. The Caltech VLBI package
. DWARF/NEWSTAR, the Westerbork Astronomical Reduction Facility.

. OLAF, the MERLIN data reduction package
. ANALYZ, the Arecibo Observatory astronomical data reduction package
. The NOAO IRAF package
. Optical identification of radio sources from Palomar Observatory Sky Sur­
vey (POSS) prints using fine­scale distance measuring machines at Ooty
and Dwingeloo, and also from the digitised CDs of the POSS.
. IDL : I have been using this rather extensively over the past two years.
CONTACT PERSONS FOR RECOMMENDATIONS:
1. Dr. Daniel Altschuler, Arecibo Observatory, HC3 Box 53995, Arecibo, PR
00612, USA. Tel: +1 787 878 2612, Fax: +1 787 878 2612,
E­mail:daniel@naic.edu
2. Dr. D.J. Saikia, National Centre for Radio Astrophysics, TIFR, Post Bag 3,
Ganeshkhind, Pune 411 007, India. Tel: 011­91­20­5697107 or 91­20­5691384/5,
Fax: 011­91­20­5692149, E­mail: djs@ncra.tifr.res.in
PUBLICATIONS:
1. Gopal­Krishna, Ghosh, T. and Saripalli, L.
``CERCO'' ­ A Compendium of Extragalactic Radio sources, Catalogues and
Observations,
1985, circulated from Tata Institute of Fundamental Research, India.
2. Gopal­Krishna, Steppe, H., Ghosh, T. and Saripalli, L.
A statistical analysis of the radio properties of a large sample of 374 optically
selected quasars.
1986, IAU Symp. 119, p. 111.
3. Ghosh, T. and Rao, A. P.
Observations of low frequency variables at Ooty,
1987, NRAO Workshop No. 20: Large­scale Surveys of the Sky, p.43.
4. Ghosh, T. and Gopal­Krishna.
A multifrequency study of radio intensity variations for active galactic nuclei of
di#erent optical classes.
1990, A&A 230, 297.
5. Saikia, D. J., Salter, C. J., Banhatti, D.G., Ghosh, T., Gothoskar, P. and
Manoharan, P.K.
The Ooty Summer Training Programme 1990,
1991, Bull. Astr. Soc. India., 19, 109.

6. Ghosh, T. and Rao, A. P.
The Galactic latitude dependence of Low Frequency Variability of extragalactic
radio sources.
1992, A&A 264, 203.
7. Kukula, M. J., Ghosh, T., Pedlar, A., Schilizzi, R. T., Miley, G. K., deBruyn,
A. G., Saikia, D.J.
High resolution radio observations of Markarian 3.
1993, MNRAS 264, 893.
8. Oppenheimer, B.R., Salter, C.J., Biggs, J., Foster, R., Ghosh, T.
Monitoring the interstellar scintillations of PSR 1933+16 : Eight epochs from
Jan 1992 to May 1993.
1993, BAAS, 25, 1358.
9. Ghosh, T., Schilizzi, R. T., Miley, G. K., deBruyn, A. G., Kukula, M. J.,
Pedlar, A., Graham, D., Saikia, D. J.,
The milliarcsecond structure of four Seyfert galaxies at #18 cm., 1993, Proc. IAU
Symp. 159 on Active Galactic Nuclei across the electromagnetic spectrum, Ed:
Blecha, A., and Courvoisier, T. (Kluwer Academic Publishers, 1994), p426.
10. Ghosh, T., Gopal­Krishna, and Rao, A. P.,
Three year monitoring of a sample of flat­spectrum radio sources at 327 MHz.
1994, A&A S, 106, 29
11. Iyengar D.R., Ghosh, T., Salter, C.J.,
Modeling the distribution of interstellar scattering at low latitudes,
1994, BAAS, 26, 1328.
12. Altschuler, D.A., Salgado, J.F., Dennison, B.K., Ghosh, T.,
Variability of extragalactic radio sources at low frequencies,
1994, BAAS, 26, 1503.
13. Jones, E.J., Ghosh, T.,
Radio­loud Seyfert Galaxies and their Environments,
1995, BAAS, 27, 1355.
14. Acevedo, F., Ghosh, T.,
Radio Frequency Interference: Radio Astronomy's Biggest Enemy
1997, BAAS, 191, 1101.
15. Salgado, J.F., Ghosh, T., Salter, C.J., Junor, W., Manoharan, P.K., 1997,
I.A.U. Coll. No. 164
Radio Emission from Galactic and Extragalactic Compact Sources,
Astronomical Society of the Pacific Conference Series, Volume 144,
eds. J.A. Zensus, G.B. Taylor, & J.M. Wrobel, P287.

16. Eder, J., Ghosh, T., Kocevski, D.D.,
Dealing with the RFI Environment at Arecibo Observatory
1998, BAAS, 193, 1118.
17. Salter, C.J., Ghosh, T., et al.,
Single­Epoch Measurements of Broadband Radio Continuum Spectra, 1998,
BAAS, 193, 107225.
18. Salgado, J.F., Salter, C.J., Ghosh, T., Manoharan, P.K., 1998, BAAS, 30,
1341.
19. Salter, C.J., Ghosh, T., Alejandro, A., Aller, M.C., Cordero, Y., Daubar, I.,
DeDeo, S., Kaplan, D.L., Kocevski, D.D., Mercado, F. A., Oppenheimer, B.D.,
Salmeron, C., 1998, BAAS, 30, 1414.
20. Salgado, J.F., Salter, C.J., Ghosh, T., Junor, W., Manoharan, P.K., 1999,
BAAS, 31, 1373.
21. Frierson, D.M., Ghosh, T., Salter, C., Eder, J., 1999, BAAS, 195, No.115.14.
22. Kukula, M., Ghosh, T., Pedlar, A., Schilizzi, R.T.
Parsec­Scale Structures in the Nuclei of Four Seyfert Galxies
1999, ApJ, 518, 117.
23. Salgado, J.F., Ghosh, T., Altschuler, D.R., Dennison, B.K., Mitchell, K.J.,
Payne, H.E.,
14­year Program Monitoring the Flux Densities of 33 radio sources at low fre­
quencies.
1999, ApJ Suppl. 120, 77.
24. Ghosh T., Eder J.A., Salter C.J., Frierson, D.M., 2000, ''Neutral Hydrogen
in Seyfert Galaxies ­ A Test for the Unification Scheme'', ASP Conference Series;
''Gas and Galaxy Evolution'', eds. J.E. Hibbard, M. Rupen, J.H. van Gorkom.
25. Hirabayashi et al.
The VSOP 5 GHz AGN Survey I. Compilation and Observations.
2000, PASJ, 52, 997.
26. Molotov, I.E., Chuprikov, A.A., Salter, C.J., Ghosh, T.,
The possibility for collaboration of Arecibo with international S2 ad­hoc array.
2001, BAAS, 33,899.
27. Salter, C.J., Ghosh, T.,
Arecibo Spectral Baselines in the Presence of Continuum Emission.
2001, BAAS, 33, 900.
28. Kanekar, N., Ghosh, T., Chengalur, J.N.,
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